Index: head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml (revision 46052) @@ -1,5218 +1,5217 @@ - Advanced Networking Synopsis This chapter covers a number of advanced networking topics. After reading this chapter, you will know: The basics of gateways and routes. How to set up USB tethering. How to set up &ieee; 802.11 and &bluetooth; devices. How to make &os; act as a bridge. How to set up network PXE booting. How to set up IPv6 on a &os; machine. How to enable and utilize the features of the Common Address Redundancy Protocol (CARP) in &os;. Before reading this chapter, you should: Understand the basics of the /etc/rc scripts. Be familiar with basic network terminology. Know how to configure and install a new &os; kernel (). Know how to install additional third-party software (). Gateways and Routes Coranth Gryphon Contributed by routing gateway subnet Routing is the mechanism that allows a system to find the network path to another system. A route is a defined pair of addresses which represent the destination and a gateway. The route indicates that when trying to get to the specified destination, send the packets through the specified gateway. There are three types of destinations: individual hosts, subnets, and default. The default route is used if no other routes apply. There are also three types of gateways: individual hosts, interfaces, also called links, and Ethernet hardware (MAC) addresses. Known routes are stored in a routing table. This section provides an overview of routing basics. It then demonstrates how to configure a &os; system as a router and offers some troubleshooting tips. Routing Basics To view the routing table of a &os; system, use &man.netstat.1;: &prompt.user; netstat -r Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire default outside-gw UGS 37 418 em0 localhost localhost UH 0 181 lo0 test0 0:e0:b5:36:cf:4f UHLW 5 63288 re0 77 10.20.30.255 link#1 UHLW 1 2421 example.com link#1 UC 0 0 host1 0:e0:a8:37:8:1e UHLW 3 4601 lo0 host2 0:e0:a8:37:8:1e UHLW 0 5 lo0 => host2.example.com link#1 UC 0 0 224 link#1 UC 0 0 The entries in this example are as follows: default The first route in this table specifies the default route. When the local system needs to make a connection to a remote host, it checks the routing table to determine if a known path exists. If the remote host matches an entry in the table, the system checks to see if it can connect using the interface specified in that entry. If the destination does not match an entry, or if all known paths fail, the system uses the entry for the default route. For hosts on a local area network, the Gateway field in the default route is set to the system which has a direct connection to the Internet. When reading this entry, verify that the Flags column indicates that the gateway is usable (UG). The default route for a machine which itself is functioning as the gateway to the outside world will be the gateway machine at the Internet Service Provider (ISP). localhost The second route is the localhost route. The interface specified in the Netif column for localhost is lo0, also known as the loopback device. This indicates that all traffic for this destination should be internal, rather than sending it out over the network. MAC address The addresses beginning with 0:e0: are MAC addresses. &os; will automatically identify any hosts, test0 in the example, on the local Ethernet and add a route for that host over the Ethernet interface, re0. This type of route has a timeout, seen in the Expire column, which is used if the host does not respond in a specific amount of time. When this happens, the route to this host will be automatically deleted. These hosts are identified using the Routing Information Protocol (RIP), which calculates routes to local hosts based upon a shortest path determination. subnet &os; will automatically add subnet routes for the local subnet. In this example, 10.20.30.255 is the broadcast address for the subnet 10.20.30 and example.com is the domain name associated with that subnet. The designation link#1 refers to the first Ethernet card in the machine. Local network hosts and local subnets have their routes automatically configured by a daemon called &man.routed.8;. If it is not running, only routes which are statically defined by the administrator will exist. host The host1 line refers to the host by its Ethernet address. Since it is the sending host, &os; knows to use the loopback interface (lo0) rather than the Ethernet interface. The two host2 lines represent aliases which were created using &man.ifconfig.8;. The => symbol after the lo0 interface says that an alias has been set in addition to the loopback address. Such routes only show up on the host that supports the alias and all other hosts on the local network will have a link#1 line for such routes. 224 The final line (destination subnet 224) deals with multicasting. Various attributes of each route can be seen in the Flags column. summarizes some of these flags and their meanings: Commonly Seen Routing Table Flags Command Purpose U The route is active (up). H The route destination is a single host. G Send anything for this destination on to this gateway, which will figure out from there where to send it. S This route was statically configured. C Clones a new route based upon this route for machines to connect to. This type of route is normally used for local networks. W The route was auto-configured based upon a local area network (clone) route. L Route involves references to Ethernet (link) hardware.
On a &os; system, the default route can defined in /etc/rc.conf by specifying the IP address of the default gateway: defaultrouter="10.20.30.1" It is also possible to manually add the route using route: &prompt.root; route add default 10.20.30.1 Note that manually added routes will not survive a reboot. For more information on manual manipulation of network routing tables, refer to &man.route.8;. Configuring a Router with Static Routes Al Hoang Contributed by dual homed hosts A &os; system can be configured as the default gateway, or router, for a network if it is a dual-homed system. A dual-homed system is a host which resides on at least two different networks. Typically, each network is connected to a separate network interface, though IP aliasing can be used to bind multiple addresses, each on a different subnet, to one physical interface. router In order for the system to forward packets between interfaces, &os; must be configured as a router. Internet standards and good engineering practice prevent the &os; Project from enabling this feature by default, but it can be configured to start at boot by adding this line to /etc/rc.conf: gateway_enable="YES" # Set to YES if this host will be a gateway To enable routing now, set the &man.sysctl.8; variable net.inet.ip.forwarding to 1. To stop routing, reset this variable to 0. BGP RIP OSPF The routing table of a router needs additional routes so it knows how to reach other networks. Routes can be either added manually using static routes or routes can be automatically learned using a routing protocol. Static routes are appropriate for small networks and this section describes how to add a static routing entry for a small network. For large networks, static routes quickly become unscalable. &os; comes with the standard BSD routing daemon &man.routed.8;, which provides the routing protocols RIP, versions 1 and 2, and IRDP. Support for the BGP and OSPF routing protocols can be installed using the net/zebra package or port. Consider the following network: INTERNET | (10.0.0.1/24) Default Router to Internet | |Interface xl0 |10.0.0.10/24 +------+ | | RouterA | | (FreeBSD gateway) +------+ | Interface xl1 | 192.168.1.1/24 | +--------------------------------+ Internal Net 1 | 192.168.1.2/24 | +------+ | | RouterB | | +------+ | 192.168.2.1/24 | Internal Net 2 In this scenario, RouterA is a &os; machine that is acting as a router to the rest of the Internet. It has a default route set to 10.0.0.1 which allows it to connect with the outside world. RouterB is already configured to use 192.168.1.1 as its default gateway. Before adding any static routes, the routing table on RouterA looks like this: &prompt.user; netstat -nr Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire default 10.0.0.1 UGS 0 49378 xl0 127.0.0.1 127.0.0.1 UH 0 6 lo0 10.0.0.0/24 link#1 UC 0 0 xl0 192.168.1.0/24 link#2 UC 0 0 xl1 With the current routing table, RouterA does not have a route to the 192.168.2.0/24 network. The following command adds the Internal Net 2 network to RouterA's routing table using 192.168.1.2 as the next hop: &prompt.root; route add -net 192.168.2.0/24 192.168.1.2 Now, RouterA can reach any host on the 192.168.2.0/24 network. However, the routing information will not persist if the &os; system reboots. If a static route needs to be persistent, add it to /etc/rc.conf: # Add Internal Net 2 as a persistent static route static_routes="internalnet2" route_internalnet2="-net 192.168.2.0/24 192.168.1.2" The static_routes configuration variable is a list of strings separated by a space, where each string references a route name. The variable route_internalnet2 contains the static route for that route name. Using more than one string in static_routes creates multiple static routes. The following shows an example of adding static routes for the 192.168.0.0/24 and 192.168.1.0/24 networks: static_routes="net1 net2" route_net1="-net 192.168.0.0/24 192.168.0.1" route_net2="-net 192.168.1.0/24 192.168.1.1" Troubleshooting When an address space is assigned to a network, the service provider configures their routing tables so that all traffic for the network will be sent to the link for the site. But how do external sites know to send their packets to the network's ISP? There is a system that keeps track of all assigned address spaces and defines their point of connection to the Internet backbone, or the main trunk lines that carry Internet traffic across the country and around the world. Each backbone machine has a copy of a master set of tables, which direct traffic for a particular network to a specific backbone carrier, and from there down the chain of service providers until it reaches a particular network. It is the task of the service provider to advertise to the backbone sites that they are the point of connection, and thus the path inward, for a site. This is known as route propagation. &man.traceroute.8; Sometimes, there is a problem with route propagation and some sites are unable to connect. Perhaps the most useful command for trying to figure out where routing is breaking down is traceroute. It is useful when ping fails. When using traceroute, include the address of the remote host to connect to. The output will show the gateway hosts along the path of the attempt, eventually either reaching the target host, or terminating because of a lack of connection. For more information, refer to &man.traceroute.8;. Multicast Considerations multicast routing kernel options MROUTING &os; natively supports both multicast applications and multicast routing. Multicast applications do not require any special configuration in order to run on &os;. Support for multicast routing requires that the following option be compiled into a custom kernel: options MROUTING The multicast routing daemon, mrouted can be installed using the net/mrouted package or port. This daemon implements the DVMRP multicast routing protocol and is configured by editing /usr/local/etc/mrouted.conf in order to set up the tunnels and DVMRP. The installation of mrouted also installs map-mbone and mrinfo, as well as their associated man pages. Refer to these for configuration examples. DVMRP has largely been replaced by the PIM protocol in many multicast installations. Refer to &man.pim.4; for more information. Wireless Networking Loader Marc Fonvieille Murray Stokely wireless networking 802.11 wireless networking Wireless Networking Basics Most wireless networks are based on the &ieee; 802.11 standards. A basic wireless network consists of multiple stations communicating with radios that broadcast in either the 2.4GHz or 5GHz band, though this varies according to the locale and is also changing to enable communication in the 2.3GHz and 4.9GHz ranges. 802.11 networks are organized in two ways. In infrastructure mode, one station acts as a master with all the other stations associating to it, the network is known as a BSS, and the master station is termed an access point (AP). In a BSS, all communication passes through the AP; even when one station wants to communicate with another wireless station, messages must go through the AP. In the second form of network, there is no master and stations communicate directly. This form of network is termed an IBSS and is commonly known as an ad-hoc network. 802.11 networks were first deployed in the 2.4GHz band using protocols defined by the &ieee; 802.11 and 802.11b standard. These specifications include the operating frequencies and the MAC layer characteristics, including framing and transmission rates, as communication can occur at various rates. Later, the 802.11a standard defined operation in the 5GHz band, including different signaling mechanisms and higher transmission rates. Still later, the 802.11g standard defined the use of 802.11a signaling and transmission mechanisms in the 2.4GHz band in such a way as to be backwards compatible with 802.11b networks. Separate from the underlying transmission techniques, 802.11 networks have a variety of security mechanisms. The original 802.11 specifications defined a simple security protocol called WEP. This protocol uses a fixed pre-shared key and the RC4 cryptographic cipher to encode data transmitted on a network. Stations must all agree on the fixed key in order to communicate. This scheme was shown to be easily broken and is now rarely used except to discourage transient users from joining networks. Current security practice is given by the &ieee; 802.11i specification that defines new cryptographic ciphers and an additional protocol to authenticate stations to an access point and exchange keys for data communication. Cryptographic keys are periodically refreshed and there are mechanisms for detecting and countering intrusion attempts. Another security protocol specification commonly used in wireless networks is termed WPA, which was a precursor to 802.11i. WPA specifies a subset of the requirements found in 802.11i and is designed for implementation on legacy hardware. Specifically, WPA requires only the TKIP cipher that is derived from the original WEP cipher. 802.11i permits use of TKIP but also requires support for a stronger cipher, AES-CCM, for encrypting data. The AES cipher was not required in WPA because it was deemed too computationally costly to be implemented on legacy hardware. The other standard to be aware of is 802.11e. It defines protocols for deploying multimedia applications, such as streaming video and voice over IP (VoIP), in an 802.11 network. Like 802.11i, 802.11e also has a precursor specification termed WME (later renamed WMM) that has been defined by an industry group as a subset of 802.11e that can be deployed now to enable multimedia applications while waiting for the final ratification of 802.11e. The most important thing to know about 802.11e and WME/WMM is that it enables prioritized traffic over a wireless network through Quality of Service (QoS) protocols and enhanced media access protocols. Proper implementation of these protocols enables high speed bursting of data and prioritized traffic flow. &os; supports networks that operate using 802.11a, 802.11b, and 802.11g. The WPA and 802.11i security protocols are likewise supported (in conjunction with any of 11a, 11b, and 11g) and QoS and traffic prioritization required by the WME/WMM protocols are supported for a limited set of wireless devices. Quick Start Connecting a computer to an existing wireless network is a very common situation. This procedure shows the steps required. Obtain the SSID (Service Set Identifier) and PSK (Pre-Shared Key) for the wireless network from the network administrator. Identify the wireless adapter. The &os; GENERIC kernel includes drivers for many common wireless adapters. If the wireless adapter is one of those models, it will be shown in the output from &man.ifconfig.8;: &prompt.user; ifconfig | grep -B3 -i wireless If a wireless adapter is not listed, an additional kernel module might be required, or it might be a model not supported by &os;. This example shows the Atheros ath0 wireless adapter. Add an entry for this network to /etc/wpa_supplicant.conf. If the file does not exist, create it. Replace myssid and mypsk with the SSID and PSK provided by the network administrator. network={ ssid="myssid" psk="mypsk" } Add entries to /etc/rc.conf to configure the network on startup: wlans_ath0="wlan0" ifconfig_wlan0="WPA SYNCDHCP" Restart the computer, or restart the network service to connect to the network: &prompt.root; service netif restart Basic Setup Kernel Configuration To use wireless networking, a wireless networking card is needed and the kernel needs to be configured with the appropriate wireless networking support. The kernel is separated into multiple modules so that only the required support needs to be configured. The most commonly used wireless devices are those that use parts made by Atheros. These devices are supported by &man.ath.4; and require the following line to be added to /boot/loader.conf: if_ath_load="YES" The Atheros driver is split up into three separate pieces: the driver (&man.ath.4;), the hardware support layer that handles chip-specific functions (&man.ath.hal.4;), and an algorithm for selecting the rate for transmitting frames. When this support is loaded as kernel modules, any dependencies are automatically handled. To load support for a different type of wireless device, specify the module for that device. This example is for devices based on the Intersil Prism parts (&man.wi.4;) driver: if_wi_load="YES" The examples in this section use an &man.ath.4; device and the device name in the examples must be changed according to the configuration. A list of available wireless drivers and supported adapters can be found in the &os; Hardware Notes, available on the Release Information page of the &os; website. If a native &os; driver for the wireless device does not exist, it may be possible to use the &windows; driver with the help of the NDIS driver wrapper. In addition, the modules that implement cryptographic support for the security protocols to use must be loaded. These are intended to be dynamically loaded on demand by the &man.wlan.4; module, but for now they must be manually configured. The following modules are available: &man.wlan.wep.4;, &man.wlan.ccmp.4;, and &man.wlan.tkip.4;. The &man.wlan.ccmp.4; and &man.wlan.tkip.4; drivers are only needed when using the WPA or 802.11i security protocols. If the network does not use encryption, &man.wlan.wep.4; support is not needed. To load these modules at boot time, add the following lines to /boot/loader.conf: wlan_wep_load="YES" wlan_ccmp_load="YES" wlan_tkip_load="YES" Once this information has been added to /boot/loader.conf, reboot the &os; box. Alternately, load the modules by hand using &man.kldload.8;. For users who do not want to use modules, it is possible to compile these drivers into the kernel by adding the following lines to a custom kernel configuration file: device wlan # 802.11 support device wlan_wep # 802.11 WEP support device wlan_ccmp # 802.11 CCMP support device wlan_tkip # 802.11 TKIP support device wlan_amrr # AMRR transmit rate control algorithm device ath # Atheros pci/cardbus NIC's device ath_hal # pci/cardbus chip support options AH_SUPPORT_AR5416 # enable AR5416 tx/rx descriptors device ath_rate_sample # SampleRate tx rate control for ath With this information in the kernel configuration file, recompile the kernel and reboot the &os; machine. Information about the wireless device should appear in the boot messages, like this: ath0: <Atheros 5212> mem 0x88000000-0x8800ffff irq 11 at device 0.0 on cardbus1 ath0: [ITHREAD] ath0: AR2413 mac 7.9 RF2413 phy 4.5 Infrastructure Mode Infrastructure (BSS) mode is the mode that is typically used. In this mode, a number of wireless access points are connected to a wired network. Each wireless network has its own name, called the SSID. Wireless clients connect to the wireless access points. &os; Clients How to Find Access Points To scan for available networks, use &man.ifconfig.8;. This request may take a few moments to complete as it requires the system to switch to each available wireless frequency and probe for available access points. Only the superuser can initiate a scan: &prompt.root; ifconfig wlan0 create wlandev ath0 &prompt.root; ifconfig wlan0 up scan SSID/MESH ID BSSID CHAN RATE S:N INT CAPS dlinkap 00:13:46:49:41:76 11 54M -90:96 100 EPS WPA WME freebsdap 00:11:95:c3:0d:ac 1 54M -83:96 100 EPS WPA The interface must be before it can scan. Subsequent scan requests do not require the interface to be marked as up again. The output of a scan request lists each BSS/IBSS network found. Besides listing the name of the network, the SSID, the output also shows the BSSID, which is the MAC address of the access point. The CAPS field identifies the type of each network and the capabilities of the stations operating there: Station Capability Codes Capability Code Meaning E Extended Service Set (ESS). Indicates that the station is part of an infrastructure network rather than an IBSS/ad-hoc network. I IBSS/ad-hoc network. Indicates that the station is part of an ad-hoc network rather than an ESS network. P Privacy. Encryption is required for all data frames exchanged within the BSS using cryptographic means such as WEP, TKIP or AES-CCMP. S Short Preamble. Indicates that the network is using short preambles, defined in 802.11b High Rate/DSSS PHY, and utilizes a 56 bit sync field rather than the 128 bit field used in long preamble mode. s Short slot time. Indicates that the 802.11g network is using a short slot time because there are no legacy (802.11b) stations present.
One can also display the current list of known networks with: &prompt.root; ifconfig wlan0 list scan This information may be updated automatically by the adapter or manually with a request. Old data is automatically removed from the cache, so over time this list may shrink unless more scans are done. Basic Settings This section provides a simple example of how to make the wireless network adapter work in &os; without encryption. Once familiar with these concepts, it is strongly recommend to use WPA to set up the wireless network. There are three basic steps to configure a wireless network: select an access point, authenticate the station, and configure an IP address. The following sections discuss each step. Selecting an Access Point Most of the time, it is sufficient to let the system choose an access point using the builtin heuristics. This is the default behaviour when an interface is marked as up or it is listed in /etc/rc.conf: wlans_ath0="wlan0" ifconfig_wlan0="DHCP" If there are multiple access points, a specific one can be selected by its SSID: wlans_ath0="wlan0" ifconfig_wlan0="ssid your_ssid_here DHCP" In an environment where there are multiple access points with the same SSID, which is often done to simplify roaming, it may be necessary to associate to one specific device. In this case, the BSSID of the access point can be specified, with or without the SSID: wlans_ath0="wlan0" ifconfig_wlan0="ssid your_ssid_here bssid xx:xx:xx:xx:xx:xx DHCP" There are other ways to constrain the choice of an access point, such as limiting the set of frequencies the system will scan on. This may be useful for a multi-band wireless card as scanning all the possible channels can be time-consuming. To limit operation to a specific band, use the parameter: wlans_ath0="wlan0" ifconfig_wlan0="mode 11g ssid your_ssid_here DHCP" This example will force the card to operate in 802.11g, which is defined only for 2.4GHz frequencies so any 5GHz channels will not be considered. This can also be achieved with the parameter, which locks operation to one specific frequency, and the parameter, to specify a list of channels for scanning. More information about these parameters can be found in &man.ifconfig.8;. Authentication Once an access point is selected, the station needs to authenticate before it can pass data. Authentication can happen in several ways. The most common scheme, open authentication, allows any station to join the network and communicate. This is the authentication to use for test purposes the first time a wireless network is setup. Other schemes require cryptographic handshakes to be completed before data traffic can flow, either using pre-shared keys or secrets, or more complex schemes that involve backend services such as RADIUS. Open authentication is the default setting. The next most common setup is WPA-PSK, also known as WPA Personal, which is described in . If using an &apple; &airport; Extreme base station for an access point, shared-key authentication together with a WEP key needs to be configured. This can be configured in /etc/rc.conf or by using &man.wpa.supplicant.8;. For a single &airport; base station, access can be configured with: wlans_ath0="wlan0" ifconfig_wlan0="authmode shared wepmode on weptxkey 1 wepkey 01234567 DHCP" In general, shared key authentication should be avoided because it uses the WEP key material in a highly-constrained manner, making it even easier to crack the key. If WEP must be used for compatibility with legacy devices, it is better to use WEP with open authentication. More information regarding WEP can be found in . Getting an <acronym>IP</acronym> Address with <acronym>DHCP</acronym> Once an access point is selected and the authentication parameters are set, an IP address must be obtained in order to communicate. Most of the time, the IP address is obtained via DHCP. To achieve that, edit /etc/rc.conf and add DHCP to the configuration for the device: wlans_ath0="wlan0" ifconfig_wlan0="DHCP" The wireless interface is now ready to bring up: &prompt.root; service netif start Once the interface is running, use &man.ifconfig.8; to see the status of the interface ath0: &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.1.100 netmask 0xffffff00 broadcast 192.168.1.255 media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g status: associated ssid dlinkap channel 11 (2462 Mhz 11g) bssid 00:13:46:49:41:76 country US ecm authmode OPEN privacy OFF txpower 21.5 bmiss 7 scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst The status: associated line means that it is connected to the wireless network. The bssid 00:13:46:49:41:76 is the MAC address of the access point and authmode OPEN indicates that the communication is not encrypted. Static <acronym>IP</acronym> Address In an IP address cannot be obtained from a DHCP server, set a fixed IP address. Replace the DHCP keyword shown above with the address information. Be sure to retain any other parameters for selecting the access point: wlans_ath0="wlan0" ifconfig_wlan0="inet 192.168.1.100 netmask 255.255.255.0 ssid your_ssid_here" <acronym>WPA</acronym> Wi-Fi Protected Access (WPA) is a security protocol used together with 802.11 networks to address the lack of proper authentication and the weakness of WEP. WPA leverages the 802.1X authentication protocol and uses one of several ciphers instead of WEP for data integrity. The only cipher required by WPA is the Temporary Key Integrity Protocol (TKIP). TKIP is a cipher that extends the basic RC4 cipher used by WEP by adding integrity checking, tamper detection, and measures for responding to detected intrusions. TKIP is designed to work on legacy hardware with only software modification. It represents a compromise that improves security but is still not entirely immune to attack. WPA also specifies the AES-CCMP cipher as an alternative to TKIP, and that is preferred when possible. For this specification, the term WPA2 or RSN is commonly used. WPA defines authentication and encryption protocols. Authentication is most commonly done using one of two techniques: by 802.1X and a backend authentication service such as RADIUS, or by a minimal handshake between the station and the access point using a pre-shared secret. The former is commonly termed WPA Enterprise and the latter is known as WPA Personal. Since most people will not set up a RADIUS backend server for their wireless network, WPA-PSK is by far the most commonly encountered configuration for WPA. The control of the wireless connection and the key negotiation or authentication with a server is done using &man.wpa.supplicant.8;. This program requires a configuration file, /etc/wpa_supplicant.conf, to run. More information regarding this file can be found in &man.wpa.supplicant.conf.5;. <acronym>WPA-PSK</acronym> WPA-PSK, also known as WPA Personal, is based on a pre-shared key (PSK) which is generated from a given password and used as the master key in the wireless network. This means every wireless user will share the same key. WPA-PSK is intended for small networks where the use of an authentication server is not possible or desired. Always use strong passwords that are sufficiently long and made from a rich alphabet so that they will not be easily guessed or attacked. The first step is the configuration of /etc/wpa_supplicant.conf with the SSID and the pre-shared key of the network: network={ ssid="freebsdap" psk="freebsdmall" } Then, in /etc/rc.conf, indicate that the wireless device configuration will be done with WPA and the IP address will be obtained with DHCP: wlans_ath0="wlan0" ifconfig_wlan0="WPA DHCP" Then, bring up the interface: &prompt.root; service netif start Starting wpa_supplicant. DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6 DHCPOFFER from 192.168.0.1 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 DHCPACK from 192.168.0.1 bound to 192.168.0.254 -- renewal in 300 seconds. wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL Or, try to configure the interface manually using the information in /etc/wpa_supplicant.conf: &prompt.root; wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf Trying to associate with 00:11:95:c3:0d:ac (SSID='freebsdap' freq=2412 MHz) Associated with 00:11:95:c3:0d:ac WPA: Key negotiation completed with 00:11:95:c3:0d:ac [PTK=CCMP GTK=CCMP] CTRL-EVENT-CONNECTED - Connection to 00:11:95:c3:0d:ac completed (auth) [id=0 id_str=] The next operation is to launch &man.dhclient.8; to get the IP address from the DHCP server: &prompt.root; dhclient wlan0 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 DHCPACK from 192.168.0.1 bound to 192.168.0.254 -- renewal in 300 seconds. &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL If /etc/rc.conf has an ifconfig_wlan0="DHCP" entry, &man.dhclient.8; will be launched automatically after &man.wpa.supplicant.8; associates with the access point. If DHCP is not possible or desired, set a static IP address after &man.wpa.supplicant.8; has authenticated the station: &prompt.root; ifconfig wlan0 inet 192.168.0.100 netmask 255.255.255.0 &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.100 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL When DHCP is not used, the default gateway and the nameserver also have to be manually set: &prompt.root; route add default your_default_router &prompt.root; echo "nameserver your_DNS_server" >> /etc/resolv.conf <acronym>WPA</acronym> with <acronym>EAP-TLS</acronym> The second way to use WPA is with an 802.1X backend authentication server. In this case, WPA is called WPA Enterprise to differentiate it from the less secure WPA Personal. Authentication in WPA Enterprise is based on the Extensible Authentication Protocol (EAP). EAP does not come with an encryption method. Instead, EAP is embedded inside an encrypted tunnel. There are many EAP authentication methods, but EAP-TLS, EAP-TTLS, and EAP-PEAP are the most common. EAP with Transport Layer Security (EAP-TLS) is a well-supported wireless authentication protocol since it was the first EAP method to be certified by the Wi-Fi Alliance. EAP-TLS requires three certificates to run: the certificate of the Certificate Authority (CA) installed on all machines, the server certificate for the authentication server, and one client certificate for each wireless client. In this EAP method, both the authentication server and wireless client authenticate each other by presenting their respective certificates, and then verify that these certificates were signed by the organization's CA. As previously, the configuration is done via /etc/wpa_supplicant.conf: network={ ssid="freebsdap" proto=RSN key_mgmt=WPA-EAP eap=TLS identity="loader" ca_cert="/etc/certs/cacert.pem" client_cert="/etc/certs/clientcert.pem" private_key="/etc/certs/clientkey.pem" private_key_passwd="freebsdmallclient" } This field indicates the network name (SSID). This example uses the RSN &ieee; 802.11i protocol, also known as WPA2. The key_mgmt line refers to the key management protocol to use. In this example, it is WPA using EAP authentication. This field indicates the EAP method for the connection. The identity field contains the identity string for EAP. The ca_cert field indicates the pathname of the CA certificate file. This file is needed to verify the server certificate. The client_cert line gives the pathname to the client certificate file. This certificate is unique to each wireless client of the network. The private_key field is the pathname to the client certificate private key file. The private_key_passwd field contains the passphrase for the private key. Then, add the following lines to /etc/rc.conf: wlans_ath0="wlan0" ifconfig_wlan0="WPA DHCP" The next step is to bring up the interface: &prompt.root; service netif start Starting wpa_supplicant. DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15 DHCPACK from 192.168.0.20 bound to 192.168.0.254 -- renewal in 300 seconds. wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL It is also possible to bring up the interface manually using &man.wpa.supplicant.8; and &man.ifconfig.8;. <acronym>WPA</acronym> with <acronym>EAP-TTLS</acronym> With EAP-TTLS, both the authentication server and the client need a certificate. With EAP-TTLS, a client certificate is optional. This method is similar to a web server which creates a secure SSL tunnel even if visitors do not have client-side certificates. EAP-TTLS uses an encrypted TLS tunnel for safe transport of the authentication data. The required configuration can be added to /etc/wpa_supplicant.conf: network={ ssid="freebsdap" proto=RSN key_mgmt=WPA-EAP eap=TTLS identity="test" password="test" ca_cert="/etc/certs/cacert.pem" phase2="auth=MD5" } This field specifies the EAP method for the connection. The identity field contains the identity string for EAP authentication inside the encrypted TLS tunnel. The password field contains the passphrase for the EAP authentication. The ca_cert field indicates the pathname of the CA certificate file. This file is needed to verify the server certificate. This field specifies the authentication method used in the encrypted TLS tunnel. In this example, EAP with MD5-Challenge is used. The inner authentication phase is often called phase2. Next, add the following lines to /etc/rc.conf: wlans_ath0="wlan0" ifconfig_wlan0="WPA DHCP" The next step is to bring up the interface: &prompt.root; service netif start Starting wpa_supplicant. DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 21 DHCPACK from 192.168.0.20 bound to 192.168.0.254 -- renewal in 300 seconds. wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL <acronym>WPA</acronym> with <acronym>EAP-PEAP</acronym> PEAPv0/EAP-MSCHAPv2 is the most common PEAP method. In this chapter, the term PEAP is used to refer to that method. Protected EAP (PEAP) is designed as an alternative to EAP-TTLS and is the most used EAP standard after EAP-TLS. In a network with mixed operating systems, PEAP should be the most supported standard after EAP-TLS. PEAP is similar to EAP-TTLS as it uses a server-side certificate to authenticate clients by creating an encrypted TLS tunnel between the client and the authentication server, which protects the ensuing exchange of authentication information. PEAP authentication differs from EAP-TTLS as it broadcasts the username in the clear and only the password is sent in the encrypted TLS tunnel. EAP-TTLS will use the TLS tunnel for both the username and password. Add the following lines to /etc/wpa_supplicant.conf to configure the EAP-PEAP related settings: network={ ssid="freebsdap" proto=RSN key_mgmt=WPA-EAP eap=PEAP identity="test" password="test" ca_cert="/etc/certs/cacert.pem" phase1="peaplabel=0" phase2="auth=MSCHAPV2" } This field specifies the EAP method for the connection. The identity field contains the identity string for EAP authentication inside the encrypted TLS tunnel. The password field contains the passphrase for the EAP authentication. The ca_cert field indicates the pathname of the CA certificate file. This file is needed to verify the server certificate. This field contains the parameters for the first phase of authentication, the TLS tunnel. According to the authentication server used, specify a specific label for authentication. Most of the time, the label will be client EAP encryption which is set by using peaplabel=0. More information can be found in &man.wpa.supplicant.conf.5;. This field specifies the authentication protocol used in the encrypted TLS tunnel. In the case of PEAP, it is auth=MSCHAPV2. Add the following to /etc/rc.conf: wlans_ath0="wlan0" ifconfig_wlan0="WPA DHCP" Then, bring up the interface: &prompt.root; service netif start Starting wpa_supplicant. DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 21 DHCPACK from 192.168.0.20 bound to 192.168.0.254 -- renewal in 300 seconds. wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst roaming MANUAL <acronym>WEP</acronym> Wired Equivalent Privacy (WEP) is part of the original 802.11 standard. There is no authentication mechanism, only a weak form of access control which is easily cracked. WEP can be set up using &man.ifconfig.8;: &prompt.root; ifconfig wlan0 create wlandev ath0 &prompt.root; ifconfig wlan0 inet 192.168.1.100 netmask 255.255.255.0 \ ssid my_net wepmode on weptxkey 3 wepkey 3:0x3456789012 The weptxkey specifies which WEP key will be used in the transmission. This example uses the third key. This must match the setting on the access point. When unsure which key is used by the access point, try 1 (the first key) for this value. The wepkey selects one of the WEP keys. It should be in the format index:key. Key 1 is used by default; the index only needs to be set when using a key other than the first key. Replace the 0x3456789012 with the key configured for use on the access point. Refer to &man.ifconfig.8; for further information. The &man.wpa.supplicant.8; facility can be used to configure a wireless interface with WEP. The example above can be set up by adding the following lines to /etc/wpa_supplicant.conf: network={ ssid="my_net" key_mgmt=NONE wep_key3=3456789012 wep_tx_keyidx=3 } Then: &prompt.root; wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf Trying to associate with 00:13:46:49:41:76 (SSID='dlinkap' freq=2437 MHz) Associated with 00:13:46:49:41:76 Ad-hoc Mode IBSS mode, also called ad-hoc mode, is designed for point to point connections. For example, to establish an ad-hoc network between the machines A and B, choose two IP addresses and a SSID. On A: &prompt.root; ifconfig wlan0 create wlandev ath0 wlanmode adhoc &prompt.root; ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 00:11:95:c3:0d:ac inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <adhoc> status: running ssid freebsdap channel 2 (2417 Mhz 11g) bssid 02:11:95:c3:0d:ac country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60 protmode CTS wme burst The adhoc parameter indicates that the interface is running in IBSS mode. B should now be able to detect A: &prompt.root; ifconfig wlan0 create wlandev ath0 wlanmode adhoc &prompt.root; ifconfig wlan0 up scan SSID/MESH ID BSSID CHAN RATE S:N INT CAPS freebsdap 02:11:95:c3:0d:ac 2 54M -64:-96 100 IS WME The I in the output confirms that A is in ad-hoc mode. Now, configure B with a different IP address: &prompt.root; ifconfig wlan0 inet 192.168.0.2 netmask 255.255.255.0 ssid freebsdap &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.2 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <adhoc> status: running ssid freebsdap channel 2 (2417 Mhz 11g) bssid 02:11:95:c3:0d:ac country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60 protmode CTS wme burst Both A and B are now ready to exchange information. &os; Host Access Points &os; can act as an Access Point (AP) which eliminates the need to buy a hardware AP or run an ad-hoc network. This can be particularly useful when a &os; machine is acting as a gateway to another network such as the Internet. Basic Settings Before configuring a &os; machine as an AP, the kernel must be configured with the appropriate networking support for the wireless card as well as the security protocols being used. For more details, see . The NDIS driver wrapper for &windows; drivers does not currently support AP operation. Only native &os; wireless drivers support AP mode. Once wireless networking support is loaded, check if the wireless device supports the host-based access point mode, also known as hostap mode: &prompt.root; ifconfig wlan0 create wlandev ath0 &prompt.root; ifconfig wlan0 list caps drivercaps=6f85edc1<STA,FF,TURBOP,IBSS,HOSTAP,AHDEMO,TXPMGT,SHSLOT,SHPREAMBLE,MONITOR,MBSS,WPA1,WPA2,BURST,WME,WDS,BGSCAN,TXFRAG> cryptocaps=1f<WEP,TKIP,AES,AES_CCM,TKIPMIC> This output displays the card's capabilities. The HOSTAP word confirms that this wireless card can act as an AP. Various supported ciphers are also listed: WEP, TKIP, and AES. This information indicates which security protocols can be used on the AP. The wireless device can only be put into hostap mode during the creation of the network pseudo-device, so a previously created device must be destroyed first: &prompt.root; ifconfig wlan0 destroy then regenerated with the correct option before setting the other parameters: &prompt.root; ifconfig wlan0 create wlandev ath0 wlanmode hostap &prompt.root; ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap mode 11g channel 1 Use &man.ifconfig.8; again to see the status of the wlan0 interface: &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 00:11:95:c3:0d:ac inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap> status: running ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60 protmode CTS wme burst dtimperiod 1 -dfs The hostap parameter indicates the interface is running in the host-based access point mode. The interface configuration can be done automatically at boot time by adding the following lines to /etc/rc.conf: wlans_ath0="wlan0" create_args_wlan0="wlanmode hostap" ifconfig_wlan0="inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap mode 11g channel 1" Host-based Access Point Without Authentication or Encryption Although it is not recommended to run an AP without any authentication or encryption, this is a simple way to check if the AP is working. This configuration is also important for debugging client issues. Once the AP is configured, initiate a scan from another wireless machine to find the AP: &prompt.root; ifconfig wlan0 create wlandev ath0 &prompt.root; ifconfig wlan0 up scan SSID/MESH ID BSSID CHAN RATE S:N INT CAPS freebsdap 00:11:95:c3:0d:ac 1 54M -66:-96 100 ES WME The client machine found the AP and can be associated with it: &prompt.root; ifconfig wlan0 inet 192.168.0.2 netmask 255.255.255.0 ssid freebsdap &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 00:11:95:d5:43:62 inet 192.168.0.2 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g status: associated ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode OPEN privacy OFF txpower 21.5 bmiss 7 scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS wme burst <acronym>WPA</acronym> Host-based Access Point This section focuses on setting up a &os; AP using the WPA security protocol. More details regarding WPA and the configuration of WPA-based wireless clients can be found in . The &man.hostapd.8; daemon is used to deal with client authentication and key management on the WPA-enabled AP. The following configuration operations are performed on the &os; machine acting as the AP. Once the AP is correctly working, &man.hostapd.8; should be automatically enabled at boot with the following line in /etc/rc.conf: hostapd_enable="YES" Before trying to configure &man.hostapd.8;, first configure the basic settings introduced in . <acronym>WPA-PSK</acronym> WPA-PSK is intended for small networks where the use of a backend authentication server is not possible or desired. The configuration is done in /etc/hostapd.conf: interface=wlan0 debug=1 ctrl_interface=/var/run/hostapd ctrl_interface_group=wheel ssid=freebsdap wpa=1 wpa_passphrase=freebsdmall wpa_key_mgmt=WPA-PSK wpa_pairwise=CCMP TKIP This field indicates the wireless interface used for the AP. This field sets the level of verbosity during the execution of &man.hostapd.8;. A value of 1 represents the minimal level. The ctrl_interface field gives the pathname of the directory used by &man.hostapd.8; to store its domain socket files for the communication with external programs such as &man.hostapd.cli.8;. The default value is used in this example. The ctrl_interface_group line sets the group which is allowed to access the control interface files. This field sets the network name. The wpa field enables WPA and specifies which WPA authentication protocol will be required. A value of 1 configures the AP for WPA-PSK. The wpa_passphrase field contains the ASCII passphrase for WPA authentication. Always use strong passwords that are sufficiently long and made from a rich alphabet so that they will not be easily guessed or attacked. The wpa_key_mgmt line refers to the key management protocol to use. This example sets WPA-PSK. The wpa_pairwise field indicates the set of accepted encryption algorithms by the AP. In this example, both TKIP (WPA) and CCMP (WPA2) ciphers are accepted. The CCMP cipher is an alternative to TKIP and is strongly preferred when possible. TKIP should be used solely for stations incapable of doing CCMP. The next step is to start &man.hostapd.8;: &prompt.root; service hostapd forcestart &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2290 inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 inet6 fe80::211:95ff:fec3:dac%ath0 prefixlen 64 scopeid 0x4 ether 00:11:95:c3:0d:ac media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap> status: associated ssid freebsdap channel 1 bssid 00:11:95:c3:0d:ac authmode WPA2/802.11i privacy MIXED deftxkey 2 TKIP 2:128-bit txpowmax 36 protmode CTS dtimperiod 1 bintval 100 Once the AP is running, the clients can associate with it. See for more details. It is possible to see the stations associated with the AP using ifconfig wlan0 list sta. <acronym>WEP</acronym> Host-based Access Point It is not recommended to use WEP for setting up an AP since there is no authentication mechanism and the encryption is easily cracked. Some legacy wireless cards only support WEP and these cards will only support an AP without authentication or encryption. The wireless device can now be put into hostap mode and configured with the correct SSID and IP address: &prompt.root; ifconfig wlan0 create wlandev ath0 wlanmode hostap &prompt.root; ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 \ ssid freebsdap wepmode on weptxkey 3 wepkey 3:0x3456789012 mode 11g The weptxkey indicates which WEP key will be used in the transmission. This example uses the third key as key numbering starts with 1. This parameter must be specified in order to encrypt the data. The wepkey sets the selected WEP key. It should be in the format index:key. If the index is not given, key 1 is set. The index needs to be set when using keys other than the first key. Use &man.ifconfig.8; to see the status of the wlan0 interface: &prompt.root; ifconfig wlan0 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 00:11:95:c3:0d:ac inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap> status: running ssid freebsdap channel 4 (2427 Mhz 11g) bssid 00:11:95:c3:0d:ac country US ecm authmode OPEN privacy ON deftxkey 3 wepkey 3:40-bit txpower 21.5 scanvalid 60 protmode CTS wme burst dtimperiod 1 -dfs From another wireless machine, it is now possible to initiate a scan to find the AP: &prompt.root; ifconfig wlan0 create wlandev ath0 &prompt.root; ifconfig wlan0 up scan SSID BSSID CHAN RATE S:N INT CAPS freebsdap 00:11:95:c3:0d:ac 1 54M 22:1 100 EPS In this example, the client machine found the AP and can associate with it using the correct parameters. See for more details. Using Both Wired and Wireless Connections A wired connection provides better performance and reliability, while a wireless connection provides flexibility and mobility. Laptop users typically want to roam seamlessly between the two types of connections. On &os;, it is possible to combine two or even more network interfaces together in a failover fashion. This type of configuration uses the most preferred and available connection from a group of network interfaces, and the operating system switches automatically when the link state changes. Link aggregation and failover is covered in and an example for using both wired and wireless connections is provided at . Troubleshooting This section describes a number of steps to help troubleshoot common wireless networking problems. If the access point is not listed when scanning, check that the configuration has not limited the wireless device to a limited set of channels. If the device cannot associate with an access point, verify that the configuration matches the settings on the access point. This includes the authentication scheme and any security protocols. Simplify the configuration as much as possible. If using a security protocol such as WPA or WEP, configure the access point for open authentication and no security to see if traffic will pass. Debugging support is provided by &man.wpa.supplicant.8;. Try running this utility manually with the option and look at the system logs. Once the system can associate with the access point, diagnose the network configuration using tools like &man.ping.8;. There are many lower-level debugging tools. Debugging messages can be enabled in the 802.11 protocol support layer using &man.wlandebug.8;. On a &os; system prior to &os; 9.1, this program can be found in /usr/src/tools/tools/net80211. For example, to enable console messages related to scanning for access points and the 802.11 protocol handshakes required to arrange communication: &prompt.root; wlandebug -i ath0 +scan+auth+debug+assoc net.wlan.0.debug: 0 => 0xc80000<assoc,auth,scan> Many useful statistics are maintained by the 802.11 layer and wlanstats, found in /usr/src/tools/tools/net80211, will dump this information. These statistics should display all errors identified by the 802.11 layer. However, some errors are identified in the device drivers that lie below the 802.11 layer so they may not show up. To diagnose device-specific problems, refer to the drivers' documentation. If the above information does not help to clarify the problem, submit a problem report and include output from the above tools. USB Tethering tether Many cellphones provide the option to share their data connection over USB (often called "tethering"). This feature uses either the RNDIS, CDC or a custom &apple; &iphone;/&ipad; protocol. &android; devices generally use the &man.urndis.4; driver. &apple; devices use the &man.ipheth.4; driver. Older devices will often use the &man.cdce.4; driver. Before attaching a device, load the appropriate driver into the kernel: &prompt.root; kldload if_urndis &prompt.root; kldload if_cdce &prompt.root; kldload if_ipheth Once the device is attached ue0 will be available for use like a normal network device. Be sure that the USB tethering option is enabled on the device. Bluetooth Pav Lucistnik Written by pav@FreeBSD.org Bluetooth Bluetooth is a wireless technology for creating personal networks operating in the 2.4 GHz unlicensed band, with a range of 10 meters. Networks are usually formed ad-hoc from portable devices such as cellular phones, handhelds, and laptops. Unlike Wi-Fi wireless technology, Bluetooth offers higher level service profiles, such as FTP-like file servers, file pushing, voice transport, serial line emulation, and more. This section describes the use of a USB Bluetooth dongle on a &os; system. It then describes the various Bluetooth protocols and utilities. Loading Bluetooth Support The Bluetooth stack in &os; is implemented using the &man.netgraph.4; framework. A broad variety of Bluetooth USB dongles is supported by &man.ng.ubt.4;. Broadcom BCM2033 based Bluetooth devices are supported by the &man.ubtbcmfw.4; and &man.ng.ubt.4; drivers. The 3Com Bluetooth PC Card 3CRWB60-A is supported by the &man.ng.bt3c.4; driver. Serial and UART based Bluetooth devices are supported by &man.sio.4;, &man.ng.h4.4;, and &man.hcseriald.8;. Before attaching a device, determine which of the above drivers it uses, then load the driver. For example, if the device uses the &man.ng.ubt.4; driver: &prompt.root; kldload ng_ubt If the Bluetooth device will be attached to the system during system startup, the system can be configured to load the module at boot time by adding the driver to /boot/loader.conf: ng_ubt_load="YES" Once the driver is loaded, plug in the USB dongle. If the driver load was successful, output similar to the following should appear on the console and in /var/log/messages: ubt0: vendor 0x0a12 product 0x0001, rev 1.10/5.25, addr 2 ubt0: Interface 0 endpoints: interrupt=0x81, bulk-in=0x82, bulk-out=0x2 ubt0: Interface 1 (alt.config 5) endpoints: isoc-in=0x83, isoc-out=0x3, wMaxPacketSize=49, nframes=6, buffer size=294 To start and stop the Bluetooth stack, use its startup script. It is a good idea to stop the stack before unplugging the device. When starting the stack, the output should be similar to the following: &prompt.root; service bluetooth start ubt0 BD_ADDR: 00:02:72:00:d4:1a Features: 0xff 0xff 0xf 00 00 00 00 00 <3-Slot> <5-Slot> <Encryption> <Slot offset> <Timing accuracy> <Switch> <Hold mode> <Sniff mode> <Park mode> <RSSI> <Channel quality> <SCO link> <HV2 packets> <HV3 packets> <u-law log> <A-law log> <CVSD> <Paging scheme> <Power control> <Transparent SCO data> Max. ACL packet size: 192 bytes Number of ACL packets: 8 Max. SCO packet size: 64 bytes Number of SCO packets: 8 Finding Other Bluetooth Devices HCI The Host Controller Interface (HCI) provides a uniform method for accessing Bluetooth baseband capabilities. In &os;, a netgraph HCI node is created for each Bluetooth device. For more details, refer to &man.ng.hci.4;. One of the most common tasks is discovery of Bluetooth devices within RF proximity. This operation is called inquiry. Inquiry and other HCI related operations are done using &man.hccontrol.8;. The example below shows how to find out which Bluetooth devices are in range. The list of devices should be displayed in a few seconds. Note that a remote device will only answer the inquiry if it is set to discoverable mode. &prompt.user; hccontrol -n ubt0hci inquiry Inquiry result, num_responses=1 Inquiry result #0 BD_ADDR: 00:80:37:29:19:a4 Page Scan Rep. Mode: 0x1 Page Scan Period Mode: 00 Page Scan Mode: 00 Class: 52:02:04 Clock offset: 0x78ef Inquiry complete. Status: No error [00] The BD_ADDR is the unique address of a Bluetooth device, similar to the MAC address of a network card. This address is needed for further communication with a device and it is possible to assign a human readable name to a BD_ADDR. Information regarding the known Bluetooth hosts is contained in /etc/bluetooth/hosts. The following example shows how to obtain the human readable name that was assigned to the remote device: &prompt.user; hccontrol -n ubt0hci remote_name_request 00:80:37:29:19:a4 BD_ADDR: 00:80:37:29:19:a4 Name: Pav's T39 If an inquiry is performed on a remote Bluetooth device, it will find the computer as your.host.name (ubt0). The name assigned to the local device can be changed at any time. The Bluetooth system provides a point-to-point connection between two Bluetooth units, or a point-to-multipoint connection which is shared among several Bluetooth devices. The following example shows how to obtain the list of active baseband connections for the local device: &prompt.user; hccontrol -n ubt0hci read_connection_list Remote BD_ADDR Handle Type Mode Role Encrypt Pending Queue State 00:80:37:29:19:a4 41 ACL 0 MAST NONE 0 0 OPEN A connection handle is useful when termination of the baseband connection is required, though it is normally not required to do this by hand. The stack will automatically terminate inactive baseband connections. &prompt.root; hccontrol -n ubt0hci disconnect 41 Connection handle: 41 Reason: Connection terminated by local host [0x16] Type hccontrol help for a complete listing of available HCI commands. Most of the HCI commands do not require superuser privileges. Device Pairing By default, Bluetooth communication is not authenticated, and any device can talk to any other device. A Bluetooth device, such as a cellular phone, may choose to require authentication to provide a particular service. Bluetooth authentication is normally done with a PIN code, an ASCII string up to 16 characters in length. The user is required to enter the same PIN code on both devices. Once the user has entered the PIN code, both devices will generate a link key. After that, the link key can be stored either in the devices or in a persistent storage. Next time, both devices will use the previously generated link key. This procedure is called pairing. Note that if the link key is lost by either device, the pairing must be repeated. The &man.hcsecd.8; daemon is responsible for handling Bluetooth authentication requests. The default configuration file is /etc/bluetooth/hcsecd.conf. An example section for a cellular phone with the PIN code set to 1234 is shown below: device { bdaddr 00:80:37:29:19:a4; name "Pav's T39"; key nokey; pin "1234"; } The only limitation on PIN codes is length. Some devices, such as Bluetooth headsets, may have a fixed PIN code built in. The switch forces &man.hcsecd.8; to stay in the foreground, so it is easy to see what is happening. Set the remote device to receive pairing and initiate the Bluetooth connection to the remote device. The remote device should indicate that pairing was accepted and request the PIN code. Enter the same PIN code listed in hcsecd.conf. Now the computer and the remote device are paired. Alternatively, pairing can be initiated on the remote device. The following line can be added to /etc/rc.conf to configure &man.hcsecd.8; to start automatically on system start: hcsecd_enable="YES" The following is a sample of the &man.hcsecd.8; daemon output: hcsecd[16484]: Got Link_Key_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4 hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', link key doesn't exist hcsecd[16484]: Sending Link_Key_Negative_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4 hcsecd[16484]: Got PIN_Code_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4 hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', PIN code exists hcsecd[16484]: Sending PIN_Code_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4 Network Access with <acronym>PPP</acronym> Profiles A Dial-Up Networking (DUN) profile can be used to configure a cellular phone as a wireless modem for connecting to a dial-up Internet access server. It can also be used to configure a computer to receive data calls from a cellular phone. Network access with a PPP profile can be used to provide LAN access for a single Bluetooth device or multiple Bluetooth devices. It can also provide PC to PC connection using PPP networking over serial cable emulation. In &os;, these profiles are implemented with &man.ppp.8; and the &man.rfcomm.pppd.8; wrapper which converts a Bluetooth connection into something PPP can use. Before a profile can be used, a new PPP label must be created in /etc/ppp/ppp.conf. Consult &man.rfcomm.pppd.8; for examples. In this example, &man.rfcomm.pppd.8; is used to open a connection to a remote device with a BD_ADDR of 00:80:37:29:19:a4 on a DUN RFCOMM channel: &prompt.root; rfcomm_pppd -a 00:80:37:29:19:a4 -c -C dun -l rfcomm-dialup The actual channel number will be obtained from the remote device using the SDP protocol. It is possible to specify the RFCOMM channel by hand, and in this case &man.rfcomm.pppd.8; will not perform the SDP query. Use &man.sdpcontrol.8; to find out the RFCOMM channel on the remote device. In order to provide network access with the PPP LAN service, &man.sdpd.8; must be running and a new entry for LAN clients must be created in /etc/ppp/ppp.conf. Consult &man.rfcomm.pppd.8; for examples. Finally, start the RFCOMM PPP server on a valid RFCOMM channel number. The RFCOMM PPP server will automatically register the Bluetooth LAN service with the local SDP daemon. The example below shows how to start the RFCOMM PPP server. &prompt.root; rfcomm_pppd -s -C 7 -l rfcomm-server Bluetooth Protocols This section provides an overview of the various Bluetooth protocols, their function, and associated utilities. Logical Link Control and Adaptation Protocol (<acronym>L2CAP</acronym>) L2CAP The Logical Link Control and Adaptation Protocol (L2CAP) provides connection-oriented and connectionless data services to upper layer protocols. L2CAP permits higher level protocols and applications to transmit and receive L2CAP data packets up to 64 kilobytes in length. L2CAP is based around the concept of channels. A channel is a logical connection on top of a baseband connection, where each channel is bound to a single protocol in a many-to-one fashion. Multiple channels can be bound to the same protocol, but a channel cannot be bound to multiple protocols. Each L2CAP packet received on a channel is directed to the appropriate higher level protocol. Multiple channels can share the same baseband connection. In &os;, a netgraph L2CAP node is created for each Bluetooth device. This node is normally connected to the downstream Bluetooth HCI node and upstream Bluetooth socket nodes. The default name for the L2CAP node is devicel2cap. For more details refer to &man.ng.l2cap.4;. A useful command is &man.l2ping.8;, which can be used to ping other devices. Some Bluetooth implementations might not return all of the data sent to them, so 0 bytes in the following example is normal. &prompt.root; l2ping -a 00:80:37:29:19:a4 0 bytes from 0:80:37:29:19:a4 seq_no=0 time=48.633 ms result=0 0 bytes from 0:80:37:29:19:a4 seq_no=1 time=37.551 ms result=0 0 bytes from 0:80:37:29:19:a4 seq_no=2 time=28.324 ms result=0 0 bytes from 0:80:37:29:19:a4 seq_no=3 time=46.150 ms result=0 The &man.l2control.8; utility is used to perform various operations on L2CAP nodes. This example shows how to obtain the list of logical connections (channels) and the list of baseband connections for the local device: &prompt.user; l2control -a 00:02:72:00:d4:1a read_channel_list L2CAP channels: Remote BD_ADDR SCID/ DCID PSM IMTU/ OMTU State 00:07:e0:00:0b:ca 66/ 64 3 132/ 672 OPEN &prompt.user; l2control -a 00:02:72:00:d4:1a read_connection_list L2CAP connections: Remote BD_ADDR Handle Flags Pending State 00:07:e0:00:0b:ca 41 O 0 OPEN Another diagnostic tool is &man.btsockstat.1;. It is similar to &man.netstat.1;, but for Bluetooth network-related data structures. The example below shows the same logical connection as &man.l2control.8; above. &prompt.user; btsockstat Active L2CAP sockets PCB Recv-Q Send-Q Local address/PSM Foreign address CID State c2afe900 0 0 00:02:72:00:d4:1a/3 00:07:e0:00:0b:ca 66 OPEN Active RFCOMM sessions L2PCB PCB Flag MTU Out-Q DLCs State c2afe900 c2b53380 1 127 0 Yes OPEN Active RFCOMM sockets PCB Recv-Q Send-Q Local address Foreign address Chan DLCI State c2e8bc80 0 250 00:02:72:00:d4:1a 00:07:e0:00:0b:ca 3 6 OPEN Radio Frequency Communication (<acronym>RFCOMM</acronym>) The RFCOMM protocol provides emulation of serial ports over the L2CAP protocol. RFCOMM is a simple transport protocol, with additional provisions for emulating the 9 circuits of RS-232 (EIATIA-232-E) serial ports. It supports up to 60 simultaneous connections (RFCOMM channels) between two Bluetooth devices. For the purposes of RFCOMM, a complete communication path involves two applications running on the communication endpoints with a communication segment between them. RFCOMM is intended to cover applications that make use of the serial ports of the devices in which they reside. The communication segment is a direct connect Bluetooth link from one device to another. RFCOMM is only concerned with the connection between the devices in the direct connect case, or between the device and a modem in the network case. RFCOMM can support other configurations, such as modules that communicate via Bluetooth wireless technology on one side and provide a wired interface on the other side. In &os;, RFCOMM is implemented at the Bluetooth sockets layer. Service Discovery Protocol (<acronym>SDP</acronym>) SDP The Service Discovery Protocol (SDP) provides the means for client applications to discover the existence of services provided by server applications as well as the attributes of those services. The attributes of a service include the type or class of service offered and the mechanism or protocol information needed to utilize the service. SDP involves communication between a SDP server and a SDP client. The server maintains a list of service records that describe the characteristics of services associated with the server. Each service record contains information about a single service. A client may retrieve information from a service record maintained by the SDP server by issuing a SDP request. If the client, or an application associated with the client, decides to use a service, it must open a separate connection to the service provider in order to utilize the service. SDP provides a mechanism for discovering services and their attributes, but it does not provide a mechanism for utilizing those services. Normally, a SDP client searches for services based on some desired characteristics of the services. However, there are times when it is desirable to discover which types of services are described by an SDP server's service records without any prior information about the services. This process of looking for any offered services is called browsing. The Bluetooth SDP server, &man.sdpd.8;, and command line client, &man.sdpcontrol.8;, are included in the standard &os; installation. The following example shows how to perform a SDP browse query. &prompt.user; sdpcontrol -a 00:01:03:fc:6e:ec browse Record Handle: 00000000 Service Class ID List: Service Discovery Server (0x1000) Protocol Descriptor List: L2CAP (0x0100) Protocol specific parameter #1: u/int/uuid16 1 Protocol specific parameter #2: u/int/uuid16 1 Record Handle: 0x00000001 Service Class ID List: Browse Group Descriptor (0x1001) Record Handle: 0x00000002 Service Class ID List: LAN Access Using PPP (0x1102) Protocol Descriptor List: L2CAP (0x0100) RFCOMM (0x0003) Protocol specific parameter #1: u/int8/bool 1 Bluetooth Profile Descriptor List: LAN Access Using PPP (0x1102) ver. 1.0 Note that each service has a list of attributes, such as the RFCOMM channel. Depending on the service, the user might need to make note of some of the attributes. Some Bluetooth implementations do not support service browsing and may return an empty list. In this case, it is possible to search for the specific service. The example below shows how to search for the OBEX Object Push (OPUSH) service: &prompt.user; sdpcontrol -a 00:01:03:fc:6e:ec search OPUSH Offering services on &os; to Bluetooth clients is done with the &man.sdpd.8; server. The following line can be added to /etc/rc.conf: sdpd_enable="YES" Then the &man.sdpd.8; daemon can be started with: &prompt.root; service sdpd start The local server application that wants to provide a Bluetooth service to remote clients will register the service with the local SDP daemon. An example of such an application is &man.rfcomm.pppd.8;. Once started, it will register the Bluetooth LAN service with the local SDP daemon. The list of services registered with the local SDP server can be obtained by issuing a SDP browse query via the local control channel: &prompt.root; sdpcontrol -l browse <acronym>OBEX</acronym> Object Push (<acronym>OPUSH</acronym>) OBEX Object Exchange (OBEX) is a widely used protocol for simple file transfers between mobile devices. Its main use is in infrared communication, where it is used for generic file transfers between notebooks or PDAs, and for sending business cards or calendar entries between cellular phones and other devices with Personal Information Manager (PIM) applications. The OBEX server and client are implemented by obexapp, which can be installed using the comms/obexapp package or port. The OBEX client is used to push and/or pull objects from the OBEX server. An example object is a business card or an appointment. The OBEX client can obtain the RFCOMM channel number from the remote device via SDP. This can be done by specifying the service name instead of the RFCOMM channel number. Supported service names are: IrMC, FTRN, and OPUSH. It is also possible to specify the RFCOMM channel as a number. Below is an example of an OBEX session where the device information object is pulled from the cellular phone, and a new object, the business card, is pushed into the phone's directory. &prompt.user; obexapp -a 00:80:37:29:19:a4 -C IrMC obex> get telecom/devinfo.txt devinfo-t39.txt Success, response: OK, Success (0x20) obex> put new.vcf Success, response: OK, Success (0x20) obex> di Success, response: OK, Success (0x20) In order to provide the OPUSH service, &man.sdpd.8; must be running and a root folder, where all incoming objects will be stored, must be created. The default path to the root folder is /var/spool/obex. Finally, start the OBEX server on a valid RFCOMM channel number. The OBEX server will automatically register the OPUSH service with the local SDP daemon. The example below shows how to start the OBEX server. &prompt.root; obexapp -s -C 10 Serial Port Profile (<acronym>SPP</acronym>) The Serial Port Profile (SPP) allows Bluetooth devices to perform serial cable emulation. This profile allows legacy applications to use Bluetooth as a cable replacement, through a virtual serial port abstraction. In &os;, &man.rfcomm.sppd.1; implements SPP and a pseudo tty is used as a virtual serial port abstraction. The example below shows how to connect to a remote device's serial port service. A RFCOMM channel does not have to be specified as &man.rfcomm.sppd.1; can obtain it from the remote device via SDP. To override this, specify a RFCOMM channel on the command line. &prompt.root; rfcomm_sppd -a 00:07:E0:00:0B:CA -t rfcomm_sppd[94692]: Starting on /dev/pts/6... /dev/pts/6 Once connected, the pseudo tty can be used as serial port: &prompt.root; cu -l /dev/pts/6 The pseudo tty is printed on stdout and can be read by wrapper scripts: PTS=`rfcomm_sppd -a 00:07:E0:00:0B:CA -t` cu -l $PTS Troubleshooting By default, when &os; is accepting a new connection, it tries to perform a role switch and become master. Some older Bluetooth devices which do not support role switching will not be able to connect. Since role switching is performed when a new connection is being established, it is not possible to ask the remote device if it supports role switching. However, there is a HCI option to disable role switching on the local side: &prompt.root; hccontrol -n ubt0hci write_node_role_switch 0 To display Bluetooth packets, use the third-party package hcidump, which can be installed using the comms/hcidump package or port. This utility is similar to &man.tcpdump.1; and can be used to display the contents of Bluetooth packets on the terminal and to dump the Bluetooth packets to a file. Bridging Andrew Thompson Written by IP subnet bridge It is sometimes useful to divide a network, such as an Ethernet segment, into network segments without having to create IP subnets and use a router to connect the segments together. A device that connects two networks together in this fashion is called a bridge. A bridge works by learning the MAC addresses of the devices on each of its network interfaces. It forwards traffic between networks only when the source and destination MAC addresses are on different networks. In many respects, a bridge is like an Ethernet switch with very few ports. A &os; system with multiple network interfaces can be configured to act as a bridge. Bridging can be useful in the following situations: Connecting Networks The basic operation of a bridge is to join two or more network segments. There are many reasons to use a host-based bridge instead of networking equipment, such as cabling constraints or firewalling. A bridge can also connect a wireless interface running in hostap mode to a wired network and act as an access point. Filtering/Traffic Shaping Firewall A bridge can be used when firewall functionality is needed without routing or Network Address Translation (NAT). An example is a small company that is connected via DSL or ISDN to an ISP. There are thirteen public IP addresses from the ISP and ten computers on the network. In this situation, using a router-based firewall is difficult because of subnetting issues. A bridge-based firewall can be configured without any IP addressing issues. Network Tap A bridge can join two network segments in order to inspect all Ethernet frames that pass between them using &man.bpf.4; and &man.tcpdump.1; on the bridge interface or by sending a copy of all frames out an additional interface known as a span port. Layer 2 VPN Two Ethernet networks can be joined across an IP link by bridging the networks to an EtherIP tunnel or a &man.tap.4; based solution such as OpenVPN. Layer 2 Redundancy A network can be connected together with multiple links and use the Spanning Tree Protocol (STP) to block redundant paths. This section describes how to configure a &os; system as a bridge using &man.if.bridge.4;. A netgraph bridging driver is also available, and is described in &man.ng.bridge.4;. Packet filtering can be used with any firewall package that hooks into the &man.pfil.9; framework. The bridge can be used as a traffic shaper with &man.altq.4; or &man.dummynet.4;. Enabling the Bridge In &os;, &man.if.bridge.4; is a kernel module which is automatically loaded by &man.ifconfig.8; when creating a bridge interface. It is also possible to compile bridge support into a custom kernel by adding device if_bridge to the custom kernel configuration file. The bridge is created using interface cloning. To create the bridge interface: &prompt.root; ifconfig bridge create bridge0 &prompt.root; ifconfig bridge0 bridge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 96:3d:4b:f1:79:7a id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200 root id 00:00:00:00:00:00 priority 0 ifcost 0 port 0 When a bridge interface is created, it is automatically assigned a randomly generated Ethernet address. The maxaddr and timeout parameters control how many MAC addresses the bridge will keep in its forwarding table and how many seconds before each entry is removed after it is last seen. The other parameters control how STP operates. Next, specify which network interfaces to add as members of the bridge. For the bridge to forward packets, all member interfaces and the bridge need to be up: &prompt.root; ifconfig bridge0 addm fxp0 addm fxp1 up &prompt.root; ifconfig fxp0 up &prompt.root; ifconfig fxp1 up The bridge can now forward Ethernet frames between fxp0 and fxp1. Add the following lines to /etc/rc.conf so the bridge is created at startup: cloned_interfaces="bridge0" ifconfig_bridge0="addm fxp0 addm fxp1 up" ifconfig_fxp0="up" ifconfig_fxp1="up" If the bridge host needs an IP address, set it on the bridge interface, not on the member interfaces. The address can be set statically or via DHCP. This example sets a static IP address: &prompt.root; ifconfig bridge0 inet 192.168.0.1/24 It is also possible to assign an IPv6 address to a bridge interface. To make the changes permanent, add the addressing information to /etc/rc.conf. When packet filtering is enabled, bridged packets will pass through the filter inbound on the originating interface on the bridge interface, and outbound on the appropriate interfaces. Either stage can be disabled. When direction of the packet flow is important, it is best to firewall on the member interfaces rather than the bridge itself. The bridge has several configurable settings for passing non-IP and IP packets, and layer2 firewalling with &man.ipfw.8;. See &man.if.bridge.4; for more information. Enabling Spanning Tree For an Ethernet network to function properly, only one active path can exist between two devices. The STP protocol detects loops and puts redundant links into a blocked state. Should one of the active links fail, STP calculates a different tree and enables one of the blocked paths to restore connectivity to all points in the network. The Rapid Spanning Tree Protocol (RSTP or 802.1w) provides backwards compatibility with legacy STP. RSTP provides faster convergence and exchanges information with neighboring switches to quickly transition to forwarding mode without creating loops. &os; supports RSTP and STP as operating modes, with RSTP being the default mode. STP can be enabled on member interfaces using &man.ifconfig.8;. For a bridge with fxp0 and fxp1 as the current interfaces, enable STP with: &prompt.root; ifconfig bridge0 stp fxp0 stp fxp1 bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether d6:cf:d5:a0:94:6d id 00:01:02:4b:d4:50 priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200 root id 00:01:02:4b:d4:50 priority 32768 ifcost 0 port 0 member: fxp0 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP> port 3 priority 128 path cost 200000 proto rstp role designated state forwarding member: fxp1 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP> port 4 priority 128 path cost 200000 proto rstp role designated state forwarding This bridge has a spanning tree ID of 00:01:02:4b:d4:50 and a priority of 32768. As the root id is the same, it indicates that this is the root bridge for the tree. Another bridge on the network also has STP enabled: bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 96:3d:4b:f1:79:7a id 00:13:d4:9a:06:7a priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200 root id 00:01:02:4b:d4:50 priority 32768 ifcost 400000 port 4 member: fxp0 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP> port 4 priority 128 path cost 200000 proto rstp role root state forwarding member: fxp1 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP> port 5 priority 128 path cost 200000 proto rstp role designated state forwarding The line root id 00:01:02:4b:d4:50 priority 32768 ifcost 400000 port 4 shows that the root bridge is 00:01:02:4b:d4:50 and has a path cost of 400000 from this bridge. The path to the root bridge is via port 4 which is fxp0. Bridge Interface Parameters Several ifconfig parameters are unique to bridge interfaces. This section summarizes some common uses for these parameters. The complete list of available parameters is described in &man.ifconfig.8;. private A private interface does not forward any traffic to any other port that is also designated as a private interface. The traffic is blocked unconditionally so no Ethernet frames will be forwarded, including ARP packets. If traffic needs to be selectively blocked, a firewall should be used instead. span A span port transmits a copy of every Ethernet frame received by the bridge. The number of span ports configured on a bridge is unlimited, but if an interface is designated as a span port, it cannot also be used as a regular bridge port. This is most useful for snooping a bridged network passively on another host connected to one of the span ports of the bridge. For example, to send a copy of all frames out the interface named fxp4: &prompt.root; ifconfig bridge0 span fxp4 sticky If a bridge member interface is marked as sticky, dynamically learned address entries are treated at static entries in the forwarding cache. Sticky entries are never aged out of the cache or replaced, even if the address is seen on a different interface. This gives the benefit of static address entries without the need to pre-populate the forwarding table. Clients learned on a particular segment of the bridge can not roam to another segment. An example of using sticky addresses is to combine the bridge with VLANs in order to isolate customer networks without wasting IP address space. Consider that CustomerA is on vlan100, CustomerB is on vlan101, and the bridge has the address 192.168.0.1: &prompt.root; ifconfig bridge0 addm vlan100 sticky vlan100 addm vlan101 sticky vlan101 &prompt.root; ifconfig bridge0 inet 192.168.0.1/24 In this example, both clients see 192.168.0.1 as their default gateway. Since the bridge cache is sticky, one host can not spoof the MAC address of the other customer in order to intercept their traffic. Any communication between the VLANs can be blocked using a firewall or, as seen in this example, private interfaces: &prompt.root; ifconfig bridge0 private vlan100 private vlan101 The customers are completely isolated from each other and the full /24 address range can be allocated without subnetting. The number of unique source MAC addresses behind an interface can be limited. Once the limit is reached, packets with unknown source addresses are dropped until an existing host cache entry expires or is removed. The following example sets the maximum number of Ethernet devices for CustomerA on vlan100 to 10: &prompt.root; ifconfig bridge0 ifmaxaddr vlan100 10 Bridge interfaces also support monitor mode, where the packets are discarded after &man.bpf.4; processing and are not processed or forwarded further. This can be used to multiplex the input of two or more interfaces into a single &man.bpf.4; stream. This is useful for reconstructing the traffic for network taps that transmit the RX/TX signals out through two separate interfaces. For example, to read the input from four network interfaces as one stream: &prompt.root; ifconfig bridge0 addm fxp0 addm fxp1 addm fxp2 addm fxp3 monitor up &prompt.root; tcpdump -i bridge0 <acronym>SNMP</acronym> Monitoring The bridge interface and STP parameters can be monitored via &man.bsnmpd.1; which is included in the &os; base system. The exported bridge MIBs conform to IETF standards so any SNMP client or monitoring package can be used to retrieve the data. To enable monitoring on the bridge, uncomment this line in /etc/snmp.config by removing the beginning # symbol: begemotSnmpdModulePath."bridge" = "/usr/lib/snmp_bridge.so" Other configuration settings, such as community names and access lists, may need to be modified in this file. See &man.bsnmpd.1; and &man.snmp.bridge.3; for more information. Once these edits are saved, add this line to /etc/rc.conf: bsnmpd_enable="YES" Then, start &man.bsnmpd.1;: &prompt.root; service bsnmpd start The following examples use the Net-SNMP software (net-mgmt/net-snmp) to query a bridge from a client system. The net-mgmt/bsnmptools port can also be used. From the SNMP client which is running Net-SNMP, add the following lines to $HOME/.snmp/snmp.conf in order to import the bridge MIB definitions: mibdirs +/usr/share/snmp/mibs mibs +BRIDGE-MIB:RSTP-MIB:BEGEMOT-MIB:BEGEMOT-BRIDGE-MIB To monitor a single bridge using the IETF BRIDGE-MIB (RFC4188): &prompt.user; snmpwalk -v 2c -c public bridge1.example.com mib-2.dot1dBridge BRIDGE-MIB::dot1dBaseBridgeAddress.0 = STRING: 66:fb:9b:6e:5c:44 BRIDGE-MIB::dot1dBaseNumPorts.0 = INTEGER: 1 ports BRIDGE-MIB::dot1dStpTimeSinceTopologyChange.0 = Timeticks: (189959) 0:31:39.59 centi-seconds BRIDGE-MIB::dot1dStpTopChanges.0 = Counter32: 2 BRIDGE-MIB::dot1dStpDesignatedRoot.0 = Hex-STRING: 80 00 00 01 02 4B D4 50 ... BRIDGE-MIB::dot1dStpPortState.3 = INTEGER: forwarding(5) BRIDGE-MIB::dot1dStpPortEnable.3 = INTEGER: enabled(1) BRIDGE-MIB::dot1dStpPortPathCost.3 = INTEGER: 200000 BRIDGE-MIB::dot1dStpPortDesignatedRoot.3 = Hex-STRING: 80 00 00 01 02 4B D4 50 BRIDGE-MIB::dot1dStpPortDesignatedCost.3 = INTEGER: 0 BRIDGE-MIB::dot1dStpPortDesignatedBridge.3 = Hex-STRING: 80 00 00 01 02 4B D4 50 BRIDGE-MIB::dot1dStpPortDesignatedPort.3 = Hex-STRING: 03 80 BRIDGE-MIB::dot1dStpPortForwardTransitions.3 = Counter32: 1 RSTP-MIB::dot1dStpVersion.0 = INTEGER: rstp(2) The dot1dStpTopChanges.0 value is two, indicating that the STP bridge topology has changed twice. A topology change means that one or more links in the network have changed or failed and a new tree has been calculated. The dot1dStpTimeSinceTopologyChange.0 value will show when this happened. To monitor multiple bridge interfaces, the private BEGEMOT-BRIDGE-MIB can be used: &prompt.user; snmpwalk -v 2c -c public bridge1.example.com enterprises.fokus.begemot.begemotBridge BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge0" = STRING: bridge0 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge2" = STRING: bridge2 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseAddress."bridge0" = STRING: e:ce:3b:5a:9e:13 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseAddress."bridge2" = STRING: 12:5e:4d:74:d:fc BEGEMOT-BRIDGE-MIB::begemotBridgeBaseNumPorts."bridge0" = INTEGER: 1 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseNumPorts."bridge2" = INTEGER: 1 ... BEGEMOT-BRIDGE-MIB::begemotBridgeStpTimeSinceTopologyChange."bridge0" = Timeticks: (116927) 0:19:29.27 centi-seconds BEGEMOT-BRIDGE-MIB::begemotBridgeStpTimeSinceTopologyChange."bridge2" = Timeticks: (82773) 0:13:47.73 centi-seconds BEGEMOT-BRIDGE-MIB::begemotBridgeStpTopChanges."bridge0" = Counter32: 1 BEGEMOT-BRIDGE-MIB::begemotBridgeStpTopChanges."bridge2" = Counter32: 1 BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge0" = Hex-STRING: 80 00 00 40 95 30 5E 31 BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge2" = Hex-STRING: 80 00 00 50 8B B8 C6 A9 To change the bridge interface being monitored via the mib-2.dot1dBridge subtree: &prompt.user; snmpset -v 2c -c private bridge1.example.com BEGEMOT-BRIDGE-MIB::begemotBridgeDefaultBridgeIf.0 s bridge2 Link Aggregation and Failover Andrew Thompson Written by lagg failover FEC LACP loadbalance roundrobin &os; provides the &man.lagg.4; interface which can be used to aggregate multiple network interfaces into one virtual interface in order to provide failover and link aggregation. Failover allows traffic to continue to flow as long as at least one aggregated network interface has an established link. Link aggregation works best on switches which support LACP, as this protocol distributes traffic bi-directionally while responding to the failure of individual links. The aggregation protocols supported by the lagg interface determine which ports are used for outgoing traffic and whether or not a specific port accepts incoming traffic. The following protocols are supported by &man.lagg.4;: failover This mode sends and receives traffic only through the master port. If the master port becomes unavailable, the next active port is used. The first interface added to the virtual interface is the master port and all subsequently added interfaces are used as failover devices. If failover to a non-master port occurs, the original port becomes master once it becomes available again. fec / loadbalance &cisco; Fast ðerchannel; (FEC) is found on older &cisco; switches. It provides a static setup and does not negotiate aggregation with the peer or exchange frames to monitor the link. If the switch supports LACP, that should be used instead. lacp The &ieee; 802.3ad Link Aggregation Control Protocol (LACP) negotiates a set of aggregable links with the peer into one or more Link Aggregated Groups (LAGs). Each LAG is composed of ports of the same speed, set to full-duplex operation, and traffic is balanced across the ports in the LAG with the greatest total speed. Typically, there is only one LAG which contains all the ports. In the event of changes in physical connectivity, LACP will quickly converge to a new configuration. LACP balances outgoing traffic across the active ports based on hashed protocol header information and accepts incoming traffic from any active port. The hash includes the Ethernet source and destination address and, if available, the VLAN tag, and the IPv4 or IPv6 source and destination address. roundrobin This mode distributes outgoing traffic using a round-robin scheduler through all active ports and accepts incoming traffic from any active port. Since this mode violates Ethernet frame ordering, it should be used with caution. Configuration Examples This section demonstrates how to configure a &cisco; switch and a &os; system for LACP load balancing. It then shows how to configure two Ethernet interfaces in failover mode as well as how to configure failover mode between an Ethernet and a wireless interface. <acronym>LACP</acronym> Aggregation with a &cisco; Switch This example connects two &man.fxp.4; Ethernet interfaces on a &os; machine to the first two Ethernet ports on a &cisco; switch as a single load balanced and fault tolerant link. More interfaces can be added to increase throughput and fault tolerance. Replace the names of the &cisco; ports, Ethernet devices, channel group number, and IP address shown in the example to match the local configuration. Frame ordering is mandatory on Ethernet links and any traffic between two stations always flows over the same physical link, limiting the maximum speed to that of one interface. The transmit algorithm attempts to use as much information as it can to distinguish different traffic flows and balance the flows across the available interfaces. On the &cisco; switch, add the FastEthernet0/1 and FastEthernet0/2 interfaces to channel group 1: interface FastEthernet0/1 channel-group 1 mode active channel-protocol lacp ! interface FastEthernet0/2 channel-group 1 mode active channel-protocol lacp On the &os; system, create the &man.lagg.4; interface using the physical interfaces fxp0 and fxp1 and bring the interfaces up with an IP address of 10.0.0.3/24: &prompt.root; ifconfig fxp0 up &prompt.root; ifconfig fxp1 up &prompt.root; ifconfig lagg0 create &prompt.root; ifconfig lagg0 up laggproto lacp laggport fxp0 laggport fxp1 10.0.0.3/24 Next, verify the status of the virtual interface: &prompt.root; ifconfig lagg0 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=8<VLAN_MTU> ether 00:05:5d:71:8d:b8 media: Ethernet autoselect status: active laggproto lacp laggport: fxp1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING> laggport: fxp0 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING> Ports marked as ACTIVE are part of the LAG that has been negotiated with the remote switch. Traffic will be transmitted and received through these active ports. Add to the above command to view the LAG identifiers. To see the port status on the &cisco; switch: switch# show lacp neighbor Flags: S - Device is requesting Slow LACPDUs F - Device is requesting Fast LACPDUs A - Device is in Active mode P - Device is in Passive mode Channel group 1 neighbors Partner's information: LACP port Oper Port Port Port Flags Priority Dev ID Age Key Number State Fa0/1 SA 32768 0005.5d71.8db8 29s 0x146 0x3 0x3D Fa0/2 SA 32768 0005.5d71.8db8 29s 0x146 0x4 0x3D For more detail, type show lacp neighbor detail. To retain this configuration across reboots, add the following entries to /etc/rc.conf on the &os; system: ifconfig_fxp0="up" ifconfig_fxp1="up" cloned_interfaces="lagg0" ifconfig_lagg0="laggproto lacp laggport fxp0 laggport fxp1 10.0.0.3/24" Failover Mode Failover mode can be used to switch over to a secondary interface if the link is lost on the master interface. To configure failover, make sure that the underlying physical interfaces are up, then create the &man.lagg.4; interface. In this example, fxp0 is the master interface, fxp1 is the secondary interface, and the virtual interface is assigned an IP address of 10.0.0.15/24: &prompt.root; ifconfig fxp0 up &prompt.root; ifconfig fxp1 up &prompt.root; ifconfig lagg0 create &prompt.root; ifconfig lagg0 up laggproto failover laggport fxp0 laggport fxp1 10.0.0.15/24 The virtual interface should look something like this: &prompt.root; ifconfig lagg0 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=8<VLAN_MTU> ether 00:05:5d:71:8d:b8 inet 10.0.0.15 netmask 0xffffff00 broadcast 10.0.0.255 media: Ethernet autoselect status: active laggproto failover laggport: fxp1 flags=0<> laggport: fxp0 flags=5<MASTER,ACTIVE> Traffic will be transmitted and received on fxp0. If the link is lost on fxp0, fxp1 will become the active link. If the link is restored on the master interface, it will once again become the active link. To retain this configuration across reboots, add the following entries to /etc/rc.conf: ifconfig_fxp0="up" ifconfig_fxp1="up" cloned_interfaces="lagg0" ifconfig_lagg0="laggproto failover laggport fxp0 laggport fxp1 10.0.0.15/24" Failover Mode Between Ethernet and Wireless Interfaces For laptop users, it is usually desirable to configure the wireless device as a secondary which is only used when the Ethernet connection is not available. With &man.lagg.4;, it is possible to configure a failover which prefers the Ethernet connection for both performance and security reasons, while maintaining the ability to transfer data over the wireless connection. This is achieved by overriding the physical wireless interface's MAC address with that of the Ethernet interface. In this example, the Ethernet interface, bge0, is the master and the wireless interface, wlan0, is the failover. The wlan0 device was created from iwn0 wireless interface, which will be configured with the MAC address of the Ethernet interface. First, determine the MAC address of the Ethernet interface: &prompt.root; ifconfig bge0 bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4> ether 00:21:70:da:ae:37 inet6 fe80::221:70ff:feda:ae37%bge0 prefixlen 64 scopeid 0x2 nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> media: Ethernet autoselect (1000baseT <full-duplex>) status: active Replace bge0 to match the system's Ethernet interface name. The ether line will contain the MAC address of the specified interface. Now, change the MAC address of the underlying wireless interface: &prompt.root; ifconfig iwn0 ether 00:21:70:da:ae:37 Bring the wireless interface up, but do not set an IP address: &prompt.root; ifconfig wlan0 create wlandev iwn0 ssid my_router up Make sure the bge0 interface is up, then create the &man.lagg.4; interface with bge0 as master with failover to wlan0: &prompt.root; ifconfig bge0 up &prompt.root; ifconfig lagg0 create &prompt.root; ifconfig lagg0 up laggproto failover laggport bge0 laggport wlan0 The virtual interface should look something like this: &prompt.root; ifconfig lagg0 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=8<VLAN_MTU> ether 00:21:70:da:ae:37 media: Ethernet autoselect status: active laggproto failover laggport: wlan0 flags=0<> laggport: bge0 flags=5<MASTER,ACTIVE> Then, start the DHCP client to obtain an IP address: &prompt.root; dhclient lagg0 To retain this configuration across reboots, add the following entries to /etc/rc.conf: ifconfig_bge0="up" ifconfig_iwn0="ether 00:21:70:da:ae:37" wlans_iwn0="wlan0" ifconfig_wlan0="WPA" cloned_interfaces="lagg0" ifconfig_lagg0="laggproto failover laggport bge0 laggport wlan0 DHCP" Diskless Operation with <acronym>PXE</acronym> Jean-François Dockès Updated by Alex Dupre Reorganized and enhanced by diskless workstation diskless operation The &intel; Preboot eXecution Environment (PXE) allows an operating system to boot over the network. For example, a &os; system can boot over the network and operate without a local disk, using file systems mounted from an NFS server. PXE support is usually available in the BIOS. To use PXE when the machine starts, select the Boot from network option in the BIOS setup or type a function key during system initialization. In order to provide the files needed for an operating system to boot over the network, a PXE setup also requires properly configured DHCP, TFTP, and NFS servers, where: Initial parameters, such as an IP address, executable boot filename and location, server name, and root path are obtained from the DHCP server. The operating system loader file is booted using TFTP. The file systems are loaded using NFS. When a computer PXE boots, it receives information over DHCP about where to obtain the initial boot loader file. After the host computer receives this information, it downloads the boot loader via TFTP and then executes the boot loader. In &os;, the boot loader file is /boot/pxeboot. After /boot/pxeboot executes, the &os; kernel is loaded and the rest of the &os; bootup sequence proceeds, as described in . This section describes how to configure these services on a &os; system so that other systems can PXE boot into &os;. Refer to &man.diskless.8; for more information. As described, the system providing these services is insecure. It should live in a protected area of a network and be untrusted by other hosts. Setting Up the <acronym>PXE</acronym> Environment Craig Rodrigues
rodrigc@FreeBSD.org
 Written by The steps shown in this section configure the built-in NFS and TFTP servers. The next section demonstrates how to install and configure the DHCP server. In this example, the directory which will contain the files used by PXE users is /b/tftpboot/FreeBSD/install. It is important that this directory exists and that the same directory name is set in both /etc/inetd.conf and /usr/local/etc/dhcpd.conf. Create the root directory which will contain a &os; installation to be NFS mounted: &prompt.root; export NFSROOTDIR=/b/tftpboot/FreeBSD/install &prompt.root; mkdir -p ${NFSROOTDIR} Enable the NFS server by adding this line to /etc/rc.conf: nfs_server_enable="YES" Export the diskless root directory via NFS by adding the following to /etc/exports: /b -ro -alldirs Start the NFS server: &prompt.root; service nfsd start Enable &man.inetd.8; by adding the following line to /etc/rc.conf: inetd_enable="YES" Uncomment the following line in /etc/inetd.conf by making sure it does not start with a # symbol: tftp dgram udp wait root /usr/libexec/tftpd tftpd -l -s /b/tftpboot Some PXE versions require the TCP version of TFTP. In this case, uncomment the second tftp line which contains stream tcp. Start &man.inetd.8;: &prompt.root; service inetd start Rebuild the &os; kernel and userland (refer to for more detailed instructions): &prompt.root; cd /usr/src &prompt.root; make buildworld &prompt.root; make buildkernel Install &os; into the directory mounted over NFS: &prompt.root; make installworld DESTDIR=${NFSROOTDIR} &prompt.root; make installkernel DESTDIR=${NFSROOTDIR} &prompt.root; make distribution DESTDIR=${NFSROOTDIR} Test that the TFTP server works and can download the boot loader which will be obtained via PXE: &prompt.root; tftp localhost tftp> get FreeBSD/install/boot/pxeboot Received 264951 bytes in 0.1 seconds Edit ${NFSROOTDIR}/etc/fstab and create an entry to mount the root file system over NFS: # Device Mountpoint FSType Options Dump Pass myhost.example.com:/b/tftpboot/FreeBSD/install / nfs ro 0 0 Replace myhost.example.com with the hostname or IP address of the NFS server. In this example, the root file system is mounted read-only in order to prevent NFS clients from potentially deleting the contents of the root file system. Set the root password in the PXE environment for client machines which are PXE booting : &prompt.root; chroot ${NFSROOTDIR} &prompt.root; passwd If needed, enable &man.ssh.1; root logins for client machines which are PXE booting by editing ${NFSROOTDIR}/etc/ssh/sshd_config and enabling PermitRootLogin. This option is documented in &man.sshd.config.5;. Perform any other needed customizations of the PXE environment in ${NFSROOTDIR}. These customizations could include things like installing packages or editing the password file with &man.vipw.8;. When booting from an NFS root volume, /etc/rc detects the NFS boot and runs /etc/rc.initdiskless. In this case, /etc and /var need to be memory backed file systems so that these directories are writable but the NFS root directory is read-only: &prompt.root; chroot ${NFSROOTDIR} &prompt.root; mkdir -p conf/base &prompt.root; tar -c -v -f conf/base/etc.cpio.gz --format cpio --gzip etc &prompt.root; tar -c -v -f conf/base/var.cpio.gz --format cpio --gzip var When the system boots, memory file systems for /etc and /var will be created and mounted and the contents of the cpio.gz files will be copied into them. Configuring the <acronym>DHCP</acronym> Server DHCP diskless operation The DHCP server does not need to be the same machine as the TFTP and NFS server, but it needs to be accessible in the network. DHCP is not part of the &os; base system but can be installed using the net/isc-dhcp42-server port or package. Once installed, edit the configuration file, /usr/local/etc/dhcpd.conf. Configure the next-server, filename, and root-path settings as seen in this example: subnet 192.168.0.0 netmask 255.255.255.0 { range 192.168.0.2 192.168.0.3 ; option subnet-mask 255.255.255.0 ; option routers 192.168.0.1 ; option broadcast-address 192.168.0.255 ; option domain-name-servers 192.168.35.35, 192.168.35.36 ; option domain-name "example.com"; # IP address of TFTP server next-server 192.168.0.1 ; # path of boot loader obtained via tftp filename "FreeBSD/install/boot/pxeboot" ; # pxeboot boot loader will try to NFS mount this directory for root FS option root-path "192.168.0.1:/b/tftpboot/FreeBSD/install/" ; } The next-server directive is used to specify the IP address of the TFTP server. The filename directive defines the path to /boot/pxeboot. A relative filename is used, meaning that /b/tftpboot is not included in the path. The root-path option defines the path to the NFS root file system. Once the edits are saved, enable NFS at boot time by adding the following line to /etc/rc.conf: dhcpd_enable="YES" Then, start the DHCP service: &prompt.root; service isc-dhcpd start Debugging <acronym>PXE</acronym> Problems Once all of the services are configured and started, PXE clients should be able to automatically load &os; over the network. If a particular client is unable to connect, when that client machine boots up, enter the BIOS configuration menu and confirm that it is set to boot from the network. This section describes some troubleshooting tips for isolating the source of the configuration problem should no clients be able to PXE boot. Use the net/wireshark package or port to debug the network traffic involved during the PXE booting process, which is illustrated in the diagram below.
<acronym>PXE</acronym> Booting Process with <acronym>NFS</acronym> Root Mount Client broadcasts a DHCPDISCOVER message. The DHCP server responds with the IP address, next-server, filename, and root-path values. The client sends a TFTP request to next-server, asking to retrieve filename. The TFTP server responds and sends filename to client. The client executes filename, which is &man.pxeboot.8;, which then loads the kernel. When the kernel executes, the root file system specified by root-path is mounted over NFS.
On the TFTP server, read /var/log/xferlog to ensure that the pxeboot file is being retrieved from the correct location. To test this example configuration: &prompt.root; tftp 192.168.0.1 tftp> get FreeBSD/install/boot/pxeboot Received 264951 bytes in 0.1 seconds The BUGS sections in &man.tftpd.8; and &man.tftp.1; document some limitations with TFTP. Make sure that the root file system can be mounted via NFS. To test this example configuration: &prompt.root; mount -t nfs 192.168.0.1:/b/tftpboot/FreeBSD/install /mnt <acronym>IPv6</acronym> Aaron Kaplan Originally Written by Tom Rhodes Restructured and Added by Brad Davis Extended by IPv6 is the new version of the well known IP protocol, also known as IPv4. IPv6 provides several advantages over IPv4 as well as many new features: Its 128-bit address space allows for 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses. This addresses the IPv4 address shortage and eventual IPv4 address exhaustion. Routers only store network aggregation addresses in their routing tables, thus reducing the average space of a routing table to 8192 entries. This addresses the scalability issues associated with IPv4, which required every allocated block of IPv4 addresses to be exchanged between Internet routers, causing their routing tables to become too large to allow efficient routing. Address autoconfiguration (RFC2462). Mandatory multicast addresses. Built-in IPsec (IP security). Simplified header structure. Support for mobile IP. IPv6-to-IPv4 transition mechanisms. &os; includes the http://www.kame.net/ IPv6 reference implementation and comes with everything needed to use IPv6. This section focuses on getting IPv6 configured and running. Background on <acronym>IPv6</acronym> Addresses There are three different types of IPv6 addresses: Unicast A packet sent to a unicast address arrives at the interface belonging to the address. Anycast These addresses are syntactically indistinguishable from unicast addresses but they address a group of interfaces. The packet destined for an anycast address will arrive at the nearest router interface. Anycast addresses are only used by routers. Multicast These addresses identify a group of interfaces. A packet destined for a multicast address will arrive at all interfaces belonging to the multicast group. The IPv4 broadcast address, usually xxx.xxx.xxx.255, is expressed by multicast addresses in IPv6. When reading an IPv6 address, the canonical form is represented as x:x:x:x:x:x:x:x, where each x represents a 16 bit hex value. An example is FEBC:A574:382B:23C1:AA49:4592:4EFE:9982. Often, an address will have long substrings of all zeros. A :: (double colon) can be used to replace one substring per address. Also, up to three leading 0s per hex value can be omitted. For example, fe80::1 corresponds to the canonical form fe80:0000:0000:0000:0000:0000:0000:0001. A third form is to write the last 32 bits using the well known IPv4 notation. For example, 2002::10.0.0.1 corresponds to the hexadecimal canonical representation 2002:0000:0000:0000:0000:0000:0a00:0001, which in turn is equivalent to 2002::a00:1. To view a &os; system's IPv6 address, use &man.ifconfig.8;: &prompt.root; ifconfig rl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.0.10 netmask 0xffffff00 broadcast 10.0.0.255 inet6 fe80::200:21ff:fe03:8e1%rl0 prefixlen 64 scopeid 0x1 ether 00:00:21:03:08:e1 media: Ethernet autoselect (100baseTX ) status: active In this example, fe80::200:21ff:fe03:8e1%rl0 is an auto-configured link-local address which was automatically generated from the MAC address. Some IPv6 addresses are reserved. A summary of these reserved addresses is seen in : Reserved <acronym>IPv6</acronym> Addresses IPv6 address Prefixlength (Bits) Description Notes :: 128 bits unspecified Equivalent to 0.0.0.0 in IPv4. ::1 128 bits loopback address Equivalent to 127.0.0.1 in IPv4. ::00:xx:xx:xx:xx 96 bits embedded IPv4 The lower 32 bits are the compatible IPv4 address. ::ff:xx:xx:xx:xx 96 bits IPv4 mapped IPv6 address The lower 32 bits are the IPv4 address for hosts which do not support IPv6. fe80::/10 10 bits link-local Equivalent to 169.254.0.0/16 in IPv4. fc00::/7 7 bits unique-local Unique local addresses are intended for local communication and are only routable within a set of cooperating sites. ff00:: 8 bits multicast   2000::-3fff:: 3 bits global unicast All global unicast addresses are assigned from this pool. The first 3 bits are 001.
For further information on the structure of IPv6 addresses, refer to RFC3513. Configuring <acronym>IPv6</acronym> To configure a &os; system as an IPv6 client, add these two lines to rc.conf: ifconfig_em0_ipv6="inet6 accept_rtadv" rtsold_enable="YES" The first line enables the specified interface to receive router solicitation messages. The second line enables the router solicitation daemon, &man.rtsol.8;. For &os; 8.x, add a third line: ipv6_enable="YES" If the interface needs a statically assigned IPv6 address, add an entry to specify the static address and associated prefix length: ifconfig_fxp0_ipv6="inet6 2001:db8:4672:6565:2026:5043:2d42:5344 prefixlen 64" On a &os; 8.x system, that line uses this format instead: ipv6_ifconfig_fxp0="2001:db8:4672:6565:2026:5043:2d42:5344" To assign a default router, specify its address: ipv6_defaultrouter="2001:db8:4672:6565::1" Connecting to a Provider In order to connect to other IPv6 networks, one must have a provider or a tunnel that supports IPv6: Contact an Internet Service Provider to see if they offer IPv6. SixXS offers tunnels with end-points all around the globe. Hurricane Electric offers tunnels with end-points all around the globe. Install the net/freenet6 package or port for a dial-up connection. This section demonstrates how to take the directions from a tunnel provider and convert them into /etc/rc.conf settings that will persist through reboots. The first /etc/rc.conf entry creates the generic tunneling interface gif0: gif_interfaces="gif0" Next, configure that interface with the IPv4 addresses of the local and remote endpoints. Replace MY_IPv4_ADDR and REMOTE_IPv4_ADDR with the actual IPv4 addresses: gifconfig_gif0="MY_IPv4_ADDR REMOTE_IPv4_ADDR" To apply the IPv6 address that has been assigned for use as the IPv6 tunnel endpoint, add this line, replacing MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR with the assigned address: ifconfig_gif0_ipv6="inet6 MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR" For &os; 8.x, that line should instead use this format: ipv6_ifconfig_gif0="MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR" Then, set the default route for the other side of the IPv6 tunnel. Replace MY_IPv6_REMOTE_TUNNEL_ENDPOINT_ADDR with the default gateway address assigned by the provider: ipv6_defaultrouter="MY_IPv6_REMOTE_TUNNEL_ENDPOINT_ADDR" If the &os; system will route IPv6 packets between the rest of the network and the world, enable the gateway using this line: ipv6_gateway_enable="YES" Router Advertisement and Host Auto Configuration This section demonstrates how to setup &man.rtadvd.8; to advertise the IPv6 default route. To enable &man.rtadvd.8;, add the following to /etc/rc.conf: rtadvd_enable="YES" It is important to specify the interface on which to do IPv6 router solicitation. For example, to tell &man.rtadvd.8; to use fxp0: rtadvd_interfaces="fxp0" Next, create the configuration file, /etc/rtadvd.conf as seen in this example: fxp0:\ :addrs#1:addr="2001:471:1f11:246::":prefixlen#64:tc=ether: Replace fxp0 with the interface to be used and 2001:471:1f11:246:: with the prefix of the allocation. For a dedicated /64 subnet, nothing else needs to be changed. Otherwise, change the prefixlen# to the correct value. <acronym>IPv6</acronym> and <acronym>IPv6</acronym> Address Mapping When IPv6 is enabled on a server, there may be a need to enable IPv4 mapped IPv6 address communication. This compatibility option allows for IPv4 addresses to be represented as IPv6 addresses. Permitting IPv6 applications to communicate with IPv4 and vice versa may be a security issue. This option may not be required in most cases and is available only for compatibility. This option will allow IPv6-only applications to work with IPv4 in a dual stack environment. This is most useful for third party applications which may not support an IPv6-only environment. To enable this feature, add the following to /etc/rc.conf: ipv6_ipv4mapping="YES" Reviewing the information in RFC 3493, section 3.6 and 3.7 as well as RFC 4038 section 4.2 may be useful to some adminstrators. Common Address Redundancy Protocol (<acronym>CARP</acronym>) Tom Rhodes Contributed by Allan Jude Updated by CARP Common Address Redundancy Protocol The Common Address Redundancy Protocol (CARP) allows multiple hosts to share the same IP address and Virtual Host ID (VHID) in order to provide high availability for one or more services. This means that one or more hosts can fail, and the other hosts will transparently take over so that users do not see a service failure. In addition to the shared IP address, each host has its own IP address for management and configuration. All of the machines that share an IP address have the same VHID. The VHID for each virtual IP address must be unique across the broadcast domain of the network interface. High availability using CARP is built into &os;, though the steps to configure it vary slightly depending upon the &os; version. This section provides the same example configuration for versions before and equal to or after &os; 10. This example configures failover support with three hosts, all with unique IP addresses, but providing the same web content. It has two different masters named hosta.example.org and hostb.example.org, with a shared backup named hostc.example.org. These machines are load balanced with a Round Robin DNS configuration. The master and backup machines are configured identically except for their hostnames and management IP addresses. These servers must have the same configuration and run the same services. When the failover occurs, requests to the service on the shared IP address can only be answered correctly if the backup server has access to the same content. The backup machine has two additional CARP interfaces, one for each of the master content server's IP addresses. When a failure occurs, the backup server will pick up the failed master machine's IP address. Using <acronym>CARP</acronym> on &os; 10 and Later Enable boot-time support for CARP by adding an entry for the carp.ko kernel module in /boot/loader.conf: carp_load="YES" To load the module now without rebooting: &prompt.root; kldload carp For users who prefer to use a custom kernel, include the following line in the custom kernel configuration file and compile the kernel as described in : device carp The hostname, management IP address and subnet mask, shared IP address, and VHID are all set by adding entries to /etc/rc.conf. This example is for hosta.example.org: hostname="hosta.example.org" ifconfig_em0="inet 192.168.1.3 netmask 255.255.255.0" ifconfig_em0_alias0="vhid 1 pass testpass alias 192.168.1.50/32" The next set of entries are for hostb.example.org. Since it represents a second master, it uses a different shared IP address and VHID. However, the passwords specified with must be identical as CARP will only listen to and accept advertisements from machines with the correct password. hostname="hostb.example.org" ifconfig_em0="inet 192.168.1.4 netmask 255.255.255.0" ifconfig_em0_alias0="vhid 2 pass testpass alias 192.168.1.51/32" The third machine, hostc.example.org, is configured to handle failover from either master. This machine is configured with two CARP VHIDs, one to handle the virtual IP address for each of the master hosts. The CARP advertising skew, , is set to ensure that the backup host advertises later than the master, since controls the order of precedence when there are multiple backup servers. hostname="hostc.example.org" ifconfig_em0="inet 192.168.1.5 netmask 255.255.255.0" ifconfig_em0_alias0="vhid 1 advskew 100 pass testpass alias 192.168.1.50/32" ifconfig_em0_alias1="vhid 2 advskew 100 pass testpass alias 192.168.1.51/32" Having two CARP VHIDs configured means that hostc.example.org will notice if either of the master servers becomes unavailable. If a master fails to advertise before the backup server, the backup server will pick up the shared IP address until the master becomes available again. Preemption is disabled by default. If preemption has been enabled, hostc.example.org might not release the virtual IP address back to the original master server. The administrator can force the backup server to return the IP address to the master with the command: &prompt.root; ifconfig em0 vhid 1 state backup Once the configuration is complete, either restart networking or reboot each system. High availability is now enabled. CARP functionality can be controlled via several &man.sysctl.8; variables documented in the &man.carp.4; manual pages. Other actions can be triggered from CARP events by using &man.devd.8;. Using <acronym>CARP</acronym> on &os; 9 and Earlier The configuration for these versions of &os; is similar to the one described in the previous section, except that a CARP device must first be created and referred to in the configuration. Enable boot-time support for CARP by loading the if_carp.ko kernel module in /boot/loader.conf: if_carp_load="YES" To load the module now without rebooting: &prompt.root; kldload carp For users who prefer to use a custom kernel, include the following line in the custom kernel configuration file and compile the kernel as described in : device carp Next, on each host, create a CARP device: &prompt.root; ifconfig carp0 create Set the hostname, management IP address, the shared IP address, and VHID by adding the required lines to /etc/rc.conf. Since a virtual CARP device is used instead of an alias, the actual subnet mask of /24 is used instead of /32. Here are the entries for hosta.example.org: hostname="hosta.example.org" ifconfig_fxp0="inet 192.168.1.3 netmask 255.255.255.0" cloned_interfaces="carp0" ifconfig_carp0="vhid 1 pass testpass 192.168.1.50/24" On hostb.example.org: hostname="hostb.example.org" ifconfig_fxp0="inet 192.168.1.4 netmask 255.255.255.0" cloned_interfaces="carp0" ifconfig_carp0="vhid 2 pass testpass 192.168.1.51/24" The third machine, hostc.example.org, is configured to handle failover from either of the master hosts: hostname="hostc.example.org" ifconfig_fxp0="inet 192.168.1.5 netmask 255.255.255.0" cloned_interfaces="carp0 carp1" ifconfig_carp0="vhid 1 advskew 100 pass testpass 192.168.1.50/24" ifconfig_carp1="vhid 2 advskew 100 pass testpass 192.168.1.51/24" Preemption is disabled in the GENERIC &os; kernel. If preemption has been enabled with a custom kernel, hostc.example.org may not release the IP address back to the original content server. The administrator can force the backup server to return the IP address to the master with the command: &prompt.root; ifconfig carp0 down && ifconfig carp0 up This should be done on the carp interface which corresponds to the correct host. Once the configuration is complete, either restart networking or reboot each system. High availability is now enabled. Index: head/en_US.ISO8859-1/books/handbook/basics/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/basics/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/basics/chapter.xml (revision 46052) @@ -1,3440 +1,3438 @@ - - UNIX Basics Synopsis This chapter covers the basic commands and functionality of the &os; operating system. Much of this material is relevant for any &unix;-like operating system. New &os; users are encouraged to read through this chapter carefully. After reading this chapter, you will know: How to use and configure virtual consoles. How to create and manage users and groups on &os;. How &unix; file permissions and &os; file flags work. The default &os; file system layout. The &os; disk organization. How to mount and unmount file systems. What processes, daemons, and signals are. What a shell is, and how to change the default login environment. How to use basic text editors. What devices and device nodes are. How to read manual pages for more information. Virtual Consoles and Terminals virtual consoles terminals console Unless &os; has been configured to automatically start a graphical environment during startup, the system will boot into a command line login prompt, as seen in this example: FreeBSD/amd64 (pc3.example.org) (ttyv0) login: The first line contains some information about the system. The amd64 indicates that the system in this example is running a 64-bit version of &os;. The hostname is pc3.example.org, and ttyv0 indicates that this is the system console. The second line is the login prompt. Since &os; is a multiuser system, it needs some way to distinguish between different users. This is accomplished by requiring every user to log into the system before gaining access to the programs on the system. Every user has a unique name username and a personal password. To log into the system console, type the username that was configured during system installation, as described in , and press Enter. Then enter the password associated with the username and press Enter. The password is not echoed for security reasons. Once the correct password is input, the message of the day (MOTD) will be displayed followed by a command prompt. Depending upon the shell that was selected when the user was created, this prompt will be a #, $, or % character. The prompt indicates that the user is now logged into the &os; system console and ready to try the available commands. Virtual Consoles While the system console can be used to interact with the system, a user working from the command line at the keyboard of a &os; system will typically instead log into a virtual console. This is because system messages are configured by default to display on the system console. These messages will appear over the command or file that the user is working on, making it difficult to concentrate on the work at hand. By default, &os; is configured to provide several virtual consoles for inputting commands. Each virtual console has its own login prompt and shell and it is easy to switch between virtual consoles. This essentially provides the command line equivalent of having several windows open at the same time in a graphical environment. The key combinations AltF1 through AltF8 have been reserved by &os; for switching between virtual consoles. Use AltF1 to switch to the system console (ttyv0), AltF2 to access the first virtual console (ttyv1), AltF3 to access the second virtual console (ttyv2), and so on. When switching from one console to the next, &os; manages the screen output. The result is an illusion of having multiple virtual screens and keyboards that can be used to type commands for &os; to run. The programs that are launched in one virtual console do not stop running when the user switches to a different virtual console. Refer to &man.syscons.4;, &man.atkbd.4;, &man.vidcontrol.1; and &man.kbdcontrol.1; for a more technical description of the &os; console and its keyboard drivers. In &os;, the number of available virtual consoles is configured in this section of /etc/ttys: # name getty type status comments # ttyv0 "/usr/libexec/getty Pc" xterm on secure # Virtual terminals ttyv1 "/usr/libexec/getty Pc" xterm on secure ttyv2 "/usr/libexec/getty Pc" xterm on secure ttyv3 "/usr/libexec/getty Pc" xterm on secure ttyv4 "/usr/libexec/getty Pc" xterm on secure ttyv5 "/usr/libexec/getty Pc" xterm on secure ttyv6 "/usr/libexec/getty Pc" xterm on secure ttyv7 "/usr/libexec/getty Pc" xterm on secure ttyv8 "/usr/X11R6/bin/xdm -nodaemon" xterm off secure To disable a virtual console, put a comment symbol (#) at the beginning of the line representing that virtual console. For example, to reduce the number of available virtual consoles from eight to four, put a # in front of the last four lines representing virtual consoles ttyv5 through ttyv8. Do not comment out the line for the system console ttyv0. Note that the last virtual console (ttyv8) is used to access the graphical environment if &xorg; has been installed and configured as described in . For a detailed description of every column in this file and the available options for the virtual consoles, refer to &man.ttys.5;. Single User Mode The &os; boot menu provides an option labelled as Boot Single User. If this option is selected, the system will boot into a special mode known as single user mode. This mode is typically used to repair a system that will not boot or to reset the root password when it is not known. While in single user mode, networking and other virtual consoles are not available. However, full root access to the system is available, and by default, the root password is not needed. For these reasons, physical access to the keyboard is needed to boot into this mode and determining who has physical access to the keyboard is something to consider when securing a &os; system. The settings which control single user mode are found in this section of /etc/ttys: # name getty type status comments # # If console is marked "insecure", then init will ask for the root password # when going to single-user mode. console none unknown off secure By default, the status is set to secure. This assumes that who has physical access to the keyboard is either not important or it is controlled by a physical security policy. If this setting is changed to insecure, the assumption is that the environment itself is insecure because anyone can access the keyboard. When this line is changed to insecure, &os; will prompt for the root password when a user selects to boot into single user mode. Be careful when changing this setting to insecure! If the root password is forgotten, booting into single user mode is still possible, but may be difficult for someone who is not familiar with the &os; booting process. Changing Console Video Modes The &os; console default video mode may be adjusted to 1024x768, 1280x1024, or any other size supported by the graphics chip and monitor. To use a different video mode load the VESA module: &prompt.root; kldload vesa To determine which video modes are supported by the hardware, use &man.vidcontrol.1;. To get a list of supported video modes issue the following: &prompt.root; vidcontrol -i mode The output of this command lists the video modes that are supported by the hardware. To select a new video mode, specify the mode using &man.vidcontrol.1; as the root user: &prompt.root; vidcontrol MODE_279 If the new video mode is acceptable, it can be permanently set on boot by adding it to /etc/rc.conf: allscreens_flags="MODE_279" Users and Basic Account Management &os; allows multiple users to use the computer at the same time. While only one user can sit in front of the screen and use the keyboard at any one time, any number of users can log in to the system through the network. To use the system, each user should have their own user account. This chapter describes: The different types of user accounts on a &os; system. How to add, remove, and modify user accounts. How to set limits to control the resources that users and groups are allowed to access. How to create groups and add users as members of a group. Account Types Since all access to the &os; system is achieved using accounts and all processes are run by users, user and account management is important. There are three main types of accounts: system accounts, user accounts, and the superuser account. System Accounts accounts system System accounts are used to run services such as DNS, mail, and web servers. The reason for this is security; if all services ran as the superuser, they could act without restriction. accounts daemon accounts operator Examples of system accounts are daemon, operator, bind, news, and www. accounts nobody nobody is the generic unprivileged system account. However, the more services that use nobody, the more files and processes that user will become associated with, and hence the more privileged that user becomes. User Accounts accounts user User accounts are assigned to real people and are used to log in and use the system. Every person accessing the system should have a unique user account. This allows the administrator to find out who is doing what and prevents users from clobbering the settings of other users. Each user can set up their own environment to accommodate their use of the system, by configuring their default shell, editor, key bindings, and language settings. Every user account on a &os; system has certain information associated with it: User name The user name is typed at the login: prompt. Each user must have a unique user name. There are a number of rules for creating valid user names which are documented in &man.passwd.5;. It is recommended to use user names that consist of eight or fewer, all lower case characters in order to maintain backwards compatibility with applications. Password Each account has an associated password. User ID (UID) The User ID (UID) is a number used to uniquely identify the user to the &os; system. Commands that allow a user name to be specified will first convert it to the UID. It is recommended to use a UID less than 65535, since higher values may cause compatibility issues with some software. Group ID (GID) The Group ID (GID) is a number used to uniquely identify the primary group that the user belongs to. Groups are a mechanism for controlling access to resources based on a user's GID rather than their UID. This can significantly reduce the size of some configuration files and allows users to be members of more than one group. It is recommended to use a GID of 65535 or lower as higher GIDs may break some software. Login class Login classes are an extension to the group mechanism that provide additional flexibility when tailoring the system to different users. Login classes are discussed further in . Password change time By default, passwords do not expire. However, password expiration can be enabled on a per-user basis, forcing some or all users to change their passwords after a certain amount of time has elapsed. Account expiry time By default, &os; does not expire accounts. When creating accounts that need a limited lifespan, such as student accounts in a school, specify the account expiry date using &man.pw.8;. After the expiry time has elapsed, the account cannot be used to log in to the system, although the account's directories and files will remain. User's full name The user name uniquely identifies the account to &os;, but does not necessarily reflect the user's real name. Similar to a comment, this information can contain spaces, uppercase characters, and be more than 8 characters long. Home directory The home directory is the full path to a directory on the system. This is the user's starting directory when the user logs in. A common convention is to put all user home directories under /home/username or /usr/home/username. Each user stores their personal files and subdirectories in their own home directory. User shell The shell provides the user's default environment for interacting with the system. There are many different kinds of shells and experienced users will have their own preferences, which can be reflected in their account settings. The Superuser Account accounts superuser (root) The superuser account, usually called root, is used to manage the system with no limitations on privileges. For this reason, it should not be used for day-to-day tasks like sending and receiving mail, general exploration of the system, or programming. The superuser, unlike other user accounts, can operate without limits, and misuse of the superuser account may result in spectacular disasters. User accounts are unable to destroy the operating system by mistake, so it is recommended to login as a user account and to only become the superuser when a command requires extra privilege. Always double and triple-check any commands issued as the superuser, since an extra space or missing character can mean irreparable data loss. There are several ways to gain superuser privilege. While one can log in as root, this is highly discouraged. Instead, use &man.su.1; to become the superuser. If - is specified when running this command, the user will also inherit the root user's environment. The user running this command must be in the wheel group or else the command will fail. The user must also know the password for the root user account. In this example, the user only becomes superuser in order to run make install as this step requires superuser privilege. Once the command completes, the user types exit to leave the superuser account and return to the privilege of their user account. Install a Program As the Superuser &prompt.user; configure &prompt.user; make &prompt.user; su - Password: &prompt.root; make install &prompt.root; exit &prompt.user; The built-in &man.su.1; framework works well for single systems or small networks with just one system administrator. An alternative is to install the security/sudo package or port. This software provides activity logging and allows the administrator to configure which users can run which commands as the superuser. Managing Accounts accounts modifying &os; provides a variety of different commands to manage user accounts. The most common commands are summarized in , followed by some examples of their usage. See the manual page for each utility for more details and usage examples. Utilities for Managing User Accounts Command Summary &man.adduser.8; The recommended command-line application for adding new users. &man.rmuser.8; The recommended command-line application for removing users. &man.chpass.1; A flexible tool for changing user database information. &man.passwd.1; The command-line tool to change user passwords. &man.pw.8; A powerful and flexible tool for modifying all aspects of user accounts.
<command>adduser</command> accounts adding adduser /usr/share/skel skeleton directory The recommended program for adding new users is &man.adduser.8;. When a new user is added, this program automatically updates /etc/passwd and /etc/group. It also creates a home directory for the new user, copies in the default configuration files from /usr/share/skel, and can optionally mail the new user a welcome message. This utility must be run as the superuser. The &man.adduser.8; utility is interactive and walks through the steps for creating a new user account. As seen in , either input the required information or press Return to accept the default value shown in square brackets. In this example, the user has been invited into the wheel group, allowing them to become the superuser with &man.su.1;. When finished, the utility will prompt to either create another user or to exit. Adding a User on &os; &prompt.root; adduser Username: jru Full name: J. Random User Uid (Leave empty for default): Login group [jru]: Login group is jru. Invite jru into other groups? []: wheel Login class [default]: Shell (sh csh tcsh zsh nologin) [sh]: zsh Home directory [/home/jru]: Home directory permissions (Leave empty for default): Use password-based authentication? [yes]: Use an empty password? (yes/no) [no]: Use a random password? (yes/no) [no]: Enter password: Enter password again: Lock out the account after creation? [no]: Username : jru Password : **** Full Name : J. Random User Uid : 1001 Class : Groups : jru wheel Home : /home/jru Shell : /usr/local/bin/zsh Locked : no OK? (yes/no): yes adduser: INFO: Successfully added (jru) to the user database. Add another user? (yes/no): no Goodbye! &prompt.root; Since the password is not echoed when typed, be careful to not mistype the password when creating the user account. <command>rmuser</command> rmuser accounts removing To completely remove a user from the system, run &man.rmuser.8; as the superuser. This command performs the following steps: Removes the user's &man.crontab.1; entry, if one exists. Removes any &man.at.1; jobs belonging to the user. Kills all processes owned by the user. Removes the user from the system's local password file. Optionally removes the user's home directory, if it is owned by the user. Removes the incoming mail files belonging to the user from /var/mail. Removes all files owned by the user from temporary file storage areas such as /tmp. Finally, removes the username from all groups to which it belongs in /etc/group. If a group becomes empty and the group name is the same as the username, the group is removed. This complements the per-user unique groups created by &man.adduser.8;. &man.rmuser.8; cannot be used to remove superuser accounts since that is almost always an indication of massive destruction. By default, an interactive mode is used, as shown in the following example. <command>rmuser</command> Interactive Account Removal &prompt.root; rmuser jru Matching password entry: jru:*:1001:1001::0:0:J. Random User:/home/jru:/usr/local/bin/zsh Is this the entry you wish to remove? y Remove user's home directory (/home/jru)? y Removing user (jru): mailspool home passwd. &prompt.root; <command>chpass</command> chpass Any user can use &man.chpass.1; to change their default shell and personal information associated with their user account. The superuser can use this utility to change additional account information for any user. When passed no options, aside from an optional username, &man.chpass.1; displays an editor containing user information. When the user exits from the editor, the user database is updated with the new information. This utility will prompt for the user's password when exiting the editor, unless the utility is run as the superuser. In , the superuser has typed chpass jru and is now viewing the fields that can be changed for this user. If jru runs this command instead, only the last six fields will be displayed and available for editing. This is shown in . Using <command>chpass</command> as Superuser #Changing user database information for jru. Login: jru Password: * Uid [#]: 1001 Gid [# or name]: 1001 Change [month day year]: Expire [month day year]: Class: Home directory: /home/jru Shell: /usr/local/bin/zsh Full Name: J. Random User Office Location: Office Phone: Home Phone: Other information: Using <command>chpass</command> as Regular User #Changing user database information for jru. Shell: /usr/local/bin/zsh Full Name: J. Random User Office Location: Office Phone: Home Phone: Other information: The commands &man.chfn.1; and &man.chsh.1; are links to &man.chpass.1;, as are &man.ypchpass.1;, &man.ypchfn.1;, and &man.ypchsh.1;. Since NIS support is automatic, specifying the yp before the command is not necessary. How to configure NIS is covered in . <command>passwd</command> passwd accounts changing password Any user can easily change their password using &man.passwd.1;. To prevent accidental or unauthorized changes, this command will prompt for the user's original password before a new password can be set: Changing Your Password &prompt.user; passwd Changing local password for jru. Old password: New password: Retype new password: passwd: updating the database... passwd: done The superuser can change any user's password by specifying the username when running &man.passwd.1;. When this utility is run as the superuser, it will not prompt for the user's current password. This allows the password to be changed when a user cannot remember the original password. Changing Another User's Password as the Superuser &prompt.root; passwd jru Changing local password for jru. New password: Retype new password: passwd: updating the database... passwd: done As with &man.chpass.1;, &man.yppasswd.1; is a link to &man.passwd.1;, so NIS works with either command. <command>pw</command> pw The &man.pw.8; utility can create, remove, modify, and display users and groups. It functions as a front end to the system user and group files. &man.pw.8; has a very powerful set of command line options that make it suitable for use in shell scripts, but new users may find it more complicated than the other commands presented in this section. Managing Groups groups /etc/groups accounts groups A group is a list of users. A group is identified by its group name and GID. In &os;, the kernel uses the UID of a process, and the list of groups it belongs to, to determine what the process is allowed to do. Most of the time, the GID of a user or process usually means the first group in the list. The group name to GID mapping is listed in /etc/group. This is a plain text file with four colon-delimited fields. The first field is the group name, the second is the encrypted password, the third the GID, and the fourth the comma-delimited list of members. For a more complete description of the syntax, refer to &man.group.5;. The superuser can modify /etc/group using a text editor. Alternatively, &man.pw.8; can be used to add and edit groups. For example, to add a group called teamtwo and then confirm that it exists: Adding a Group Using &man.pw.8; &prompt.root; pw groupadd teamtwo &prompt.root; pw groupshow teamtwo teamtwo:*:1100: In this example, 1100 is the GID of teamtwo. Right now, teamtwo has no members. This command will add jru as a member of teamtwo. Adding User Accounts to a New Group Using &man.pw.8; &prompt.root; pw groupmod teamtwo -M jru &prompt.root; pw groupshow teamtwo teamtwo:*:1100:jru The argument to is a comma-delimited list of users to be added to a new (empty) group or to replace the members of an existing group. To the user, this group membership is different from (and in addition to) the user's primary group listed in the password file. This means that the user will not show up as a member when using with &man.pw.8;, but will show up when the information is queried via &man.id.1; or a similar tool. When &man.pw.8; is used to add a user to a group, it only manipulates /etc/group and does not attempt to read additional data from /etc/passwd. Adding a New Member to a Group Using &man.pw.8; &prompt.root; pw groupmod teamtwo -m db &prompt.root; pw groupshow teamtwo teamtwo:*:1100:jru,db In this example, the argument to is a comma-delimited list of users who are to be added to the group. Unlike the previous example, these users are appended to the group and do not replace existing users in the group. Using &man.id.1; to Determine Group Membership &prompt.user; id jru uid=1001(jru) gid=1001(jru) groups=1001(jru), 1100(teamtwo) In this example, jru is a member of the groups jru and teamtwo. For more information about this command and the format of /etc/group, refer to &man.pw.8; and &man.group.5;. Permissions UNIX In &os;, every file and directory has an associated set of permissions and several utilities are available for viewing and modifying these permissions. Understanding how permissions work is necessary to make sure that users are able to access the files that they need and are unable to improperly access the files used by the operating system or owned by other users. This section discusses the traditional &unix; permissions used in &os;. For finer grained file system access control, refer to . In &unix;, basic permissions are assigned using three types of access: read, write, and execute. These access types are used to determine file access to the file's owner, group, and others (everyone else). The read, write, and execute permissions can be represented as the letters r, w, and x. They can also be represented as binary numbers as each permission is either on or off (0). When represented as a number, the order is always read as rwx, where r has an on value of 4, w has an on value of 2 and x has an on value of 1. Table 4.1 summarizes the possible numeric and alphabetic possibilities. When reading the Directory Listing column, a - is used to represent a permission that is set to off. permissions file permissions &unix; Permissions Value Permission Directory Listing 0 No read, no write, no execute --- 1 No read, no write, execute --x 2 No read, write, no execute -w- 3 No read, write, execute -wx 4 Read, no write, no execute r-- 5 Read, no write, execute r-x 6 Read, write, no execute rw- 7 Read, write, execute rwx
&man.ls.1; directories Use the argument to &man.ls.1; to view a long directory listing that includes a column of information about a file's permissions for the owner, group, and everyone else. For example, a ls -l in an arbitrary directory may show: &prompt.user; ls -l total 530 -rw-r--r-- 1 root wheel 512 Sep 5 12:31 myfile -rw-r--r-- 1 root wheel 512 Sep 5 12:31 otherfile -rw-r--r-- 1 root wheel 7680 Sep 5 12:31 email.txt The first (leftmost) character in the first column indicates whether this file is a regular file, a directory, a special character device, a socket, or any other special pseudo-file device. In this example, the - indicates a regular file. The next three characters, rw- in this example, give the permissions for the owner of the file. The next three characters, r--, give the permissions for the group that the file belongs to. The final three characters, r--, give the permissions for the rest of the world. A dash means that the permission is turned off. In this example, the permissions are set so the owner can read and write to the file, the group can read the file, and the rest of the world can only read the file. According to the table above, the permissions for this file would be 644, where each digit represents the three parts of the file's permission. How does the system control permissions on devices? &os; treats most hardware devices as a file that programs can open, read, and write data to. These special device files are stored in /dev/. Directories are also treated as files. They have read, write, and execute permissions. The executable bit for a directory has a slightly different meaning than that of files. When a directory is marked executable, it means it is possible to change into that directory using &man.cd.1;. This also means that it is possible to access the files within that directory, subject to the permissions on the files themselves. In order to perform a directory listing, the read permission must be set on the directory. In order to delete a file that one knows the name of, it is necessary to have write and execute permissions to the directory containing the file. There are more permission bits, but they are primarily used in special circumstances such as setuid binaries and sticky directories. For more information on file permissions and how to set them, refer to &man.chmod.1;. Symbolic Permissions Tom Rhodes Contributed by permissions symbolic Symbolic permissions use characters instead of octal values to assign permissions to files or directories. Symbolic permissions use the syntax of (who) (action) (permissions), where the following values are available: Option Letter Represents (who) u User (who) g Group owner (who) o Other (who) a All (world) (action) + Adding permissions (action) - Removing permissions (action) = Explicitly set permissions (permissions) r Read (permissions) w Write (permissions) x Execute (permissions) t Sticky bit (permissions) s Set UID or GID These values are used with &man.chmod.1;, but with letters instead of numbers. For example, the following command would block other users from accessing FILE: &prompt.user; chmod go= FILE A comma separated list can be provided when more than one set of changes to a file must be made. For example, the following command removes the group and world write permission on FILE, and adds the execute permissions for everyone: &prompt.user; chmod go-w,a+x FILE &os; File Flags Tom Rhodes Contributed by In addition to file permissions, &os; supports the use of file flags. These flags add an additional level of security and control over files, but not directories. With file flags, even root can be prevented from removing or altering files. File flags are modified using &man.chflags.1;. For example, to enable the system undeletable flag on the file file1, issue the following command: &prompt.root; chflags sunlink file1 To disable the system undeletable flag, put a no in front of the : &prompt.root; chflags nosunlink file1 To view the flags of a file, use with &man.ls.1;: &prompt.root; ls -lo file1 -rw-r--r-- 1 trhodes trhodes sunlnk 0 Mar 1 05:54 file1 Several file flags may only be added or removed by the root user. In other cases, the file owner may set its file flags. Refer to &man.chflags.1; and &man.chflags.2; for more information. The <literal>setuid</literal>, <literal>setgid</literal>, and <literal>sticky</literal> Permissions Tom Rhodes Contributed by Other than the permissions already discussed, there are three other specific settings that all administrators should know about. They are the setuid, setgid, and sticky permissions. These settings are important for some &unix; operations as they provide functionality not normally granted to normal users. To understand them, the difference between the real user ID and effective user ID must be noted. The real user ID is the UID who owns or starts the process. The effective UID is the user ID the process runs as. As an example, &man.passwd.1; runs with the real user ID when a user changes their password. However, in order to update the password database, the command runs as the effective ID of the root user. This allows users to change their passwords without seeing a Permission Denied error. The setuid permission may be set by prefixing a permission set with the number four (4) as shown in the following example: &prompt.root; chmod 4755 suidexample.sh The permissions on suidexample.sh now look like the following: -rwsr-xr-x 1 trhodes trhodes 63 Aug 29 06:36 suidexample.sh Note that a s is now part of the permission set designated for the file owner, replacing the executable bit. This allows utilities which need elevated permissions, such as &man.passwd.1;. The nosuid &man.mount.8; option will cause such binaries to silently fail without alerting the user. That option is not completely reliable as a nosuid wrapper may be able to circumvent it. To view this in real time, open two terminals. On one, type passwd as a normal user. While it waits for a new password, check the process table and look at the user information for &man.passwd.1;: In terminal A: Changing local password for trhodes Old Password: In terminal B: &prompt.root; ps aux | grep passwd trhodes 5232 0.0 0.2 3420 1608 0 R+ 2:10AM 0:00.00 grep passwd root 5211 0.0 0.2 3620 1724 2 I+ 2:09AM 0:00.01 passwd Although &man.passwd.1; is run as a normal user, it is using the effective UID of root. The setgid permission performs the same function as the setuid permission; except that it alters the group settings. When an application or utility executes with this setting, it will be granted the permissions based on the group that owns the file, not the user who started the process. To set the setgid permission on a file, provide &man.chmod.1; with a leading two (2): &prompt.root; chmod 2755 sgidexample.sh In the following listing, notice that the s is now in the field designated for the group permission settings: -rwxr-sr-x 1 trhodes trhodes 44 Aug 31 01:49 sgidexample.sh In these examples, even though the shell script in question is an executable file, it will not run with a different EUID or effective user ID. This is because shell scripts may not access the &man.setuid.2; system calls. The setuid and setgid permission bits may lower system security, by allowing for elevated permissions. The third special permission, the sticky bit, can strengthen the security of a system. When the sticky bit is set on a directory, it allows file deletion only by the file owner. This is useful to prevent file deletion in public directories, such as /tmp, by users who do not own the file. To utilize this permission, prefix the permission set with a one (1): &prompt.root; chmod 1777 /tmp The sticky bit permission will display as a t at the very end of the permission set: &prompt.root; ls -al / | grep tmp drwxrwxrwt 10 root wheel 512 Aug 31 01:49 tmp Directory Structure directory hierarchy The &os; directory hierarchy is fundamental to obtaining an overall understanding of the system. The most important directory is root or, /. This directory is the first one mounted at boot time and it contains the base system necessary to prepare the operating system for multi-user operation. The root directory also contains mount points for other file systems that are mounted during the transition to multi-user operation. A mount point is a directory where additional file systems can be grafted onto a parent file system (usually the root file system). This is further described in . Standard mount points include /usr/, /var/, /tmp/, /mnt/, and /cdrom/. These directories are usually referenced to entries in /etc/fstab. This file is a table of various file systems and mount points and is read by the system. Most of the file systems in /etc/fstab are mounted automatically at boot time from the script &man.rc.8; unless their entry includes . Details can be found in . A complete description of the file system hierarchy is available in &man.hier.7;. The following table provides a brief overview of the most common directories. Directory Description / Root directory of the file system. /bin/ User utilities fundamental to both single-user and multi-user environments. /boot/ Programs and configuration files used during operating system bootstrap. /boot/defaults/ Default boot configuration files. Refer to &man.loader.conf.5; for details. /dev/ Device nodes. Refer to &man.intro.4; for details. /etc/ System configuration files and scripts. /etc/defaults/ Default system configuration files. Refer to &man.rc.8; for details. /etc/mail/ Configuration files for mail transport agents such as &man.sendmail.8;. /etc/namedb/ &man.named.8; configuration files. /etc/periodic/ Scripts that run daily, weekly, and monthly, via &man.cron.8;. Refer to &man.periodic.8; for details. /etc/ppp/ &man.ppp.8; configuration files. /mnt/ Empty directory commonly used by system administrators as a temporary mount point. /proc/ Process file system. Refer to &man.procfs.5;, &man.mount.procfs.8; for details. /rescue/ Statically linked programs for emergency recovery as described in &man.rescue.8;. /root/ Home directory for the root account. /sbin/ System programs and administration utilities fundamental to both single-user and multi-user environments. /tmp/ Temporary files which are usually not preserved across a system reboot. A memory-based file system is often mounted at /tmp. This can be automated using the tmpmfs-related variables of &man.rc.conf.5; or with an entry in /etc/fstab; refer to &man.mdmfs.8; for details. /usr/ The majority of user utilities and applications. /usr/bin/ Common utilities, programming tools, and applications. /usr/include/ Standard C include files. /usr/lib/ Archive libraries. /usr/libdata/ Miscellaneous utility data files. /usr/libexec/ System daemons and system utilities executed by other programs. /usr/local/ Local executables and libraries. Also used as the default destination for the &os; ports framework. Within /usr/local, the general layout sketched out by &man.hier.7; for /usr should be used. Exceptions are the man directory, which is directly under /usr/local rather than under /usr/local/share, and the ports documentation is in share/doc/port. /usr/obj/ Architecture-specific target tree produced by building the /usr/src tree. /usr/ports/ The &os; Ports Collection (optional). /usr/sbin/ System daemons and system utilities executed by users. /usr/share/ Architecture-independent files. /usr/src/ BSD and/or local source files. /var/ Multi-purpose log, temporary, transient, and spool files. A memory-based file system is sometimes mounted at /var. This can be automated using the varmfs-related variables in &man.rc.conf.5; or with an entry in /etc/fstab; refer to &man.mdmfs.8; for details. /var/log/ Miscellaneous system log files. /var/mail/ User mailbox files. /var/spool/ Miscellaneous printer and mail system spooling directories. /var/tmp/ Temporary files which are usually preserved across a system reboot, unless /var is a memory-based file system. /var/yp/ NIS maps. Disk Organization The smallest unit of organization that &os; uses to find files is the filename. Filenames are case-sensitive, which means that readme.txt and README.TXT are two separate files. &os; does not use the extension of a file to determine whether the file is a program, document, or some other form of data. Files are stored in directories. A directory may contain no files, or it may contain many hundreds of files. A directory can also contain other directories, allowing a hierarchy of directories within one another in order to organize data. Files and directories are referenced by giving the file or directory name, followed by a forward slash, /, followed by any other directory names that are necessary. For example, if the directory foo contains a directory bar which contains the file readme.txt, the full name, or path, to the file is foo/bar/readme.txt. Note that this is different from &windows; which uses \ to separate file and directory names. &os; does not use drive letters, or other drive names in the path. For example, one would not type c:\foo\bar\readme.txt on &os;. Directories and files are stored in a file system. Each file system contains exactly one directory at the very top level, called the root directory for that file system. This root directory can contain other directories. One file system is designated the root file system or /. Every other file system is mounted under the root file system. No matter how many disks are on the &os; system, every directory appears to be part of the same disk. Consider three file systems, called A, B, and C. Each file system has one root directory, which contains two other directories, called A1, A2 (and likewise B1, B2 and C1, C2). Call A the root file system. If &man.ls.1; is used to view the contents of this directory, it will show two subdirectories, A1 and A2. The directory tree looks like this: / | +--- A1 | `--- A2 A file system must be mounted on to a directory in another file system. When mounting file system B on to the directory A1, the root directory of B replaces A1, and the directories in B appear accordingly: / | +--- A1 | | | +--- B1 | | | `--- B2 | `--- A2 Any files that are in the B1 or B2 directories can be reached with the path /A1/B1 or /A1/B2 as necessary. Any files that were in /A1 have been temporarily hidden. They will reappear if B is unmounted from A. If B had been mounted on A2 then the diagram would look like this: / | +--- A1 | `--- A2 | +--- B1 | `--- B2 and the paths would be /A2/B1 and /A2/B2 respectively. File systems can be mounted on top of one another. Continuing the last example, the C file system could be mounted on top of the B1 directory in the B file system, leading to this arrangement: / | +--- A1 | `--- A2 | +--- B1 | | | +--- C1 | | | `--- C2 | `--- B2 Or C could be mounted directly on to the A file system, under the A1 directory: / | +--- A1 | | | +--- C1 | | | `--- C2 | `--- A2 | +--- B1 | `--- B2 It is entirely possible to have one large root file system, and not need to create any others. There are some drawbacks to this approach, and one advantage. Benefits of Multiple File Systems Different file systems can have different mount options. For example, the root file system can be mounted read-only, making it impossible for users to inadvertently delete or edit a critical file. Separating user-writable file systems, such as /home, from other file systems allows them to be mounted nosuid. This option prevents the suid/guid bits on executables stored on the file system from taking effect, possibly improving security. &os; automatically optimizes the layout of files on a file system, depending on how the file system is being used. So a file system that contains many small files that are written frequently will have a different optimization to one that contains fewer, larger files. By having one big file system this optimization breaks down. &os;'s file systems are robust if power is lost. However, a power loss at a critical point could still damage the structure of the file system. By splitting data over multiple file systems it is more likely that the system will still come up, making it easier to restore from backup as necessary. Benefit of a Single File System File systems are a fixed size. If you create a file system when you install &os; and give it a specific size, you may later discover that you need to make the partition bigger. This is not easily accomplished without backing up, recreating the file system with the new size, and then restoring the backed up data. &os; features the &man.growfs.8; command, which makes it possible to increase the size of file system on the fly, removing this limitation. File systems are contained in partitions. This does not have the same meaning as the common usage of the term partition (for example, &ms-dos; partition), because of &os;'s &unix; heritage. Each partition is identified by a letter from a through to h. Each partition can contain only one file system, which means that file systems are often described by either their typical mount point in the file system hierarchy, or the letter of the partition they are contained in. &os; also uses disk space for swap space to provide virtual memory. This allows your computer to behave as though it has much more memory than it actually does. When &os; runs out of memory, it moves some of the data that is not currently being used to the swap space, and moves it back in (moving something else out) when it needs it. Some partitions have certain conventions associated with them. Partition Convention a Normally contains the root file system. b Normally contains swap space. c Normally the same size as the enclosing slice. This allows utilities that need to work on the entire slice, such as a bad block scanner, to work on the c partition. A file system would not normally be created on this partition. d Partition d used to have a special meaning associated with it, although that is now gone and d may work as any normal partition. Disks in &os; are divided into slices, referred to in &windows; as partitions, which are numbered from 1 to 4. These are then divided into partitions, which contain file systems, and are labeled using letters. slices partitions dangerously dedicated Slice numbers follow the device name, prefixed with an s, starting at 1. So da0s1 is the first slice on the first SCSI drive. There can only be four physical slices on a disk, but there can be logical slices inside physical slices of the appropriate type. These extended slices are numbered starting at 5, so ada0s5 is the first extended slice on the first SATA disk. These devices are used by file systems that expect to occupy a slice. Slices, dangerously dedicated physical drives, and other drives contain partitions, which are represented as letters from a to h. This letter is appended to the device name, so da0a is the a partition on the first da drive, which is dangerously dedicated. ada1s3e is the fifth partition in the third slice of the second SATA disk drive. Finally, each disk on the system is identified. A disk name starts with a code that indicates the type of disk, and then a number, indicating which disk it is. Unlike slices, disk numbering starts at 0. Common codes are listed in . When referring to a partition, include the disk name, s, the slice number, and then the partition letter. Examples are shown in . shows a conceptual model of a disk layout. When installing &os;, configure the disk slices, create partitions within the slice to be used for &os;, create a file system or swap space in each partition, and decide where each file system will be mounted. Disk Device Names Drive Type Drive Device Name SATA and IDE hard drives ada or ad SCSI hard drives and USB storage devices da SATA and IDE CD-ROM drives cd or acd SCSI CD-ROM drives cd Floppy drives fd Assorted non-standard CD-ROM drives mcd for Mitsumi CD-ROM and scd for Sony CD-ROM devices SCSI tape drives sa IDE tape drives ast RAID drives Examples include aacd for &adaptec; AdvancedRAID, mlxd and mlyd for &mylex;, amrd for AMI &megaraid;, idad for Compaq Smart RAID, twed for &tm.3ware; RAID.
Sample Disk, Slice, and Partition Names Name Meaning ada0s1a The first partition (a) on the first slice (s1) on the first IDE disk (ada0). da1s2e The fifth partition (e) on the second slice (s2) on the second SCSI disk (da1). Conceptual Model of a Disk This diagram shows &os;'s view of the first IDE disk attached to the system. Assume that the disk is 4 GB in size, and contains two 2 GB slices (&ms-dos; partitions). The first slice contains a &ms-dos; disk, C:, and the second slice contains a &os; installation. This example &os; installation has three data partitions, and a swap partition. The three partitions will each hold a file system. Partition a will be used for the root file system, e for the /var/ directory hierarchy, and f for the /usr/ directory hierarchy. .-----------------. --. | | | | DOS / Windows | | : : > First slice, ad0s1 : : | | | | :=================: ==: --. | | | Partition a, mounted as / | | | > referred to as ad0s2a | | | | | :-----------------: ==: | | | | Partition b, used as swap | | | > referred to as ad0s2b | | | | | :-----------------: ==: | Partition c, no | | | Partition e, used as /var > file system, all | | > referred to as ad0s2e | of FreeBSD slice, | | | | ad0s2c :-----------------: ==: | | | | | : : | Partition f, used as /usr | : : > referred to as ad0s2f | : : | | | | | | | | --' | `-----------------' --' Mounting and Unmounting File Systems The file system is best visualized as a tree, rooted, as it were, at /. /dev, /usr, and the other directories in the root directory are branches, which may have their own branches, such as /usr/local, and so on. root file system There are various reasons to house some of these directories on separate file systems. /var contains the directories log/, spool/, and various types of temporary files, and as such, may get filled up. Filling up the root file system is not a good idea, so splitting /var from / is often favorable. Another common reason to contain certain directory trees on other file systems is if they are to be housed on separate physical disks, or are separate virtual disks, such as Network File System mounts, described in , or CDROM drives. The <filename>fstab</filename> File file systems mounted with fstab During the boot process (), file systems listed in /etc/fstab are automatically mounted except for the entries containing . This file contains entries in the following format: device /mount-point fstype options dumpfreq passno device An existing device name as explained in . mount-point An existing directory on which to mount the file system. fstype The file system type to pass to &man.mount.8;. The default &os; file system is ufs. options Either for read-write file systems, or for read-only file systems, followed by any other options that may be needed. A common option is for file systems not normally mounted during the boot sequence. Other options are listed in &man.mount.8;. dumpfreq Used by &man.dump.8; to determine which file systems require dumping. If the field is missing, a value of zero is assumed. passno Determines the order in which file systems should be checked. File systems that should be skipped should have their passno set to zero. The root file system needs to be checked before everything else and should have its passno set to one. The other file systems should be set to values greater than one. If more than one file system has the same passno, &man.fsck.8; will attempt to check file systems in parallel if possible. Refer to &man.fstab.5; for more information on the format of /etc/fstab and its options. Using &man.mount.8; file systems mounting File systems are mounted using &man.mount.8;. The most basic syntax is as follows: &prompt.root; mount device mountpoint This command provides many options which are described in &man.mount.8;, The most commonly used options include: Mount Options Mount all the file systems listed in /etc/fstab, except those marked as noauto, excluded by the flag, or those that are already mounted. Do everything except for the actual mount system call. This option is useful in conjunction with the flag to determine what &man.mount.8; is actually trying to do. Force the mount of an unclean file system (dangerous), or the revocation of write access when downgrading a file system's mount status from read-write to read-only. Mount the file system read-only. This is identical to using . fstype Mount the specified file system type or mount only file systems of the given type, if is included. ufs is the default file system type. Update mount options on the file system. Be verbose. Mount the file system read-write. The following options can be passed to as a comma-separated list: nosuid Do not interpret setuid or setgid flags on the file system. This is also a useful security option. Using &man.umount.8; file systems unmounting To unmount a file system use &man.umount.8;. This command takes one parameter which can be a mountpoint, device name, or . All forms take to force unmounting, and for verbosity. Be warned that is not generally a good idea as it might crash the computer or damage data on the file system. To unmount all mounted file systems, or just the file system types listed after , use or . Note that does not attempt to unmount the root file system. Processes and Daemons &os; is a multi-tasking operating system. Each program running at any one time is called a process. Every running command starts at least one new process and there are a number of system processes that are run by &os;. Each process is uniquely identified by a number called a process ID (PID). Similar to files, each process has one owner and group, and the owner and group permissions are used to determine which files and devices the process can open. Most processes also have a parent process that started them. For example, the shell is a process, and any command started in the shell is a process which has the shell as its parent process. The exception is a special process called &man.init.8; which is always the first process to start at boot time and which always has a PID of 1. Some programs are not designed to be run with continuous user input and disconnect from the terminal at the first opportunity. For example, a web server responds to web requests, rather than user input. Mail servers are another example of this type of application. These types of programs are known as daemons. The term daemon comes from Greek mythology and represents an entity that is neither good nor evil, and which invisibly performs useful tasks. This is why the BSD mascot is the cheerful-looking daemon with sneakers and a pitchfork. There is a convention to name programs that normally run as daemons with a trailing d. For example, BIND is the Berkeley Internet Name Domain, but the actual program that executes is named. The Apache web server program is httpd and the line printer spooling daemon is lpd. This is only a naming convention. For example, the main mail daemon for the Sendmail application is sendmail, and not maild. Viewing Processes To see the processes running on the system, use &man.ps.1; or &man.top.1;. To display a static list of the currently running processes, their PIDs, how much memory they are using, and the command they were started with, use &man.ps.1;. To display all the running processes and update the display every few seconds in order to interactively see what the computer is doing, use &man.top.1;. By default, &man.ps.1; only shows the commands that are running and owned by the user. For example: &prompt.user; ps PID TT STAT TIME COMMAND 8203 0 Ss 0:00.59 /bin/csh 8895 0 R+ 0:00.00 ps The output from &man.ps.1; is organized into a number of columns. The PID column displays the process ID. PIDs are assigned starting at 1, go up to 99999, then wrap around back to the beginning. However, a PID is not reassigned if it is already in use. The TT column shows the tty the program is running on and STAT shows the program's state. TIME is the amount of time the program has been running on the CPU. This is usually not the elapsed time since the program was started, as most programs spend a lot of time waiting for things to happen before they need to spend time on the CPU. Finally, COMMAND is the command that was used to start the program. A number of different options are available to change the information that is displayed. One of the most useful sets is auxww, where displays information about all the running processes of all users, displays the username and memory usage of the process' owner, displays information about daemon processes, and causes &man.ps.1; to display the full command line for each process, rather than truncating it once it gets too long to fit on the screen. The output from &man.top.1; is similar: &prompt.user; top last pid: 9609; load averages: 0.56, 0.45, 0.36 up 0+00:20:03 10:21:46 107 processes: 2 running, 104 sleeping, 1 zombie CPU: 6.2% user, 0.1% nice, 8.2% system, 0.4% interrupt, 85.1% idle Mem: 541M Active, 450M Inact, 1333M Wired, 4064K Cache, 1498M Free ARC: 992M Total, 377M MFU, 589M MRU, 250K Anon, 5280K Header, 21M Other Swap: 2048M Total, 2048M Free PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND 557 root 1 -21 r31 136M 42296K select 0 2:20 9.96% Xorg 8198 dru 2 52 0 449M 82736K select 3 0:08 5.96% kdeinit4 8311 dru 27 30 0 1150M 187M uwait 1 1:37 0.98% firefox 431 root 1 20 0 14268K 1728K select 0 0:06 0.98% moused 9551 dru 1 21 0 16600K 2660K CPU3 3 0:01 0.98% top 2357 dru 4 37 0 718M 141M select 0 0:21 0.00% kdeinit4 8705 dru 4 35 0 480M 98M select 2 0:20 0.00% kdeinit4 8076 dru 6 20 0 552M 113M uwait 0 0:12 0.00% soffice.bin 2623 root 1 30 10 12088K 1636K select 3 0:09 0.00% powerd 2338 dru 1 20 0 440M 84532K select 1 0:06 0.00% kwin 1427 dru 5 22 0 605M 86412K select 1 0:05 0.00% kdeinit4 The output is split into two sections. The header (the first five or six lines) shows the PID of the last process to run, the system load averages (which are a measure of how busy the system is), the system uptime (time since the last reboot) and the current time. The other figures in the header relate to how many processes are running, how much memory and swap space has been used, and how much time the system is spending in different CPU states. If the ZFS file system module has been loaded, an ARC line indicates how much data was read from the memory cache instead of from disk. Below the header is a series of columns containing similar information to the output from &man.ps.1;, such as the PID, username, amount of CPU time, and the command that started the process. By default, &man.top.1; also displays the amount of memory space taken by the process. This is split into two columns: one for total size and one for resident size. Total size is how much memory the application has needed and the resident size is how much it is actually using now. &man.top.1; automatically updates the display every two seconds. A different interval can be specified with . Killing Processes One way to communicate with any running process or daemon is to send a signal using &man.kill.1;. There are a number of different signals; some have a specific meaning while others are described in the application's documentation. A user can only send a signal to a process they own and sending a signal to someone else's process will result in a permission denied error. The exception is the root user, who can send signals to anyone's processes. The operating system can also send a signal to a process. If an application is badly written and tries to access memory that it is not supposed to, &os; will send the process the Segmentation Violation signal (SIGSEGV). If an application has been written to use the &man.alarm.3; system call to be alerted after a period of time has elapsed, it will be sent the Alarm signal (SIGALRM). Two signals can be used to stop a process: SIGTERM and SIGKILL. SIGTERM is the polite way to kill a process as the process can read the signal, close any log files it may have open, and attempt to finish what it is doing before shutting down. In some cases, a process may ignore SIGTERM if it is in the middle of some task that can not be interrupted. SIGKILL can not be ignored by a process. Sending a SIGKILL to a process will usually stop that process there and then. There are a few tasks that can not be interrupted. For example, if the process is trying to read from a file that is on another computer on the network, and the other computer is unavailable, the process is said to be uninterruptible. Eventually the process will time out, typically after two minutes. As soon as this time out occurs the process will be killed.. Other commonly used signals are SIGHUP, SIGUSR1, and SIGUSR2. Since these are general purpose signals, different applications will respond differently. For example, after changing a web server's configuration file, the web server needs to be told to re-read its configuration. Restarting httpd would result in a brief outage period on the web server. Instead, send the daemon the SIGHUP signal. Be aware that different daemons will have different behavior, so refer to the documentation for the daemon to determine if SIGHUP will achieve the desired results. Sending a Signal to a Process This example shows how to send a signal to &man.inetd.8;. The &man.inetd.8; configuration file is /etc/inetd.conf, and &man.inetd.8; will re-read this configuration file when it is sent a SIGHUP. Find the PID of the process to send the signal to using &man.pgrep.1;. In this example, the PID for &man.inetd.8; is 198: &prompt.user; pgrep -l inetd 198 inetd -wW Use &man.kill.1; to send the signal. Because &man.inetd.8; is owned by root, use &man.su.1; to become root first. &prompt.user; su Password: &prompt.root; /bin/kill -s HUP 198 Like most &unix; commands, &man.kill.1; will not print any output if it is successful. If a signal is sent to a process not owned by that user, the message kill: PID: Operation not permitted will be displayed. Mistyping the PID will either send the signal to the wrong process, which could have negative results, or will send the signal to a PID that is not currently in use, resulting in the error kill: PID: No such process. Why Use <command>/bin/kill</command>? Many shells provide kill as a built in command, meaning that the shell will send the signal directly, rather than running /bin/kill. Be aware that different shells have a different syntax for specifying the name of the signal to send. Rather than try to learn all of them, it can be simpler to specify /bin/kill. When sending other signals, substitute TERM or KILL with the name of the signal. Killing a random process on the system is a bad idea. In particular, &man.init.8;, PID 1, is special. Running /bin/kill -s KILL 1 is a quick, and unrecommended, way to shutdown the system. Always double check the arguments to &man.kill.1; before pressing Return. Shells shells command line A shell provides a command line interface for interacting with the operating system. A shell receives commands from the input channel and executes them. Many shells provide built in functions to help with everyday tasks such as file management, file globbing, command line editing, command macros, and environment variables. &os; comes with several shells, including the Bourne shell (&man.sh.1;) and the extended C shell (&man.tcsh.1;). Other shells are available from the &os; Ports Collection, such as zsh and bash. The shell that is used is really a matter of taste. A C programmer might feel more comfortable with a C-like shell such as &man.tcsh.1;. A &linux; user might prefer bash. Each shell has unique properties that may or may not work with a user's preferred working environment, which is why there is a choice of which shell to use. One common shell feature is filename completion. After a user types the first few letters of a command or filename and presses Tab, the shell completes the rest of the command or filename. Consider two files called foobar and football. To delete foobar, the user might type rm foo and press Tab to complete the filename. But the shell only shows rm foo. It was unable to complete the filename because both foobar and football start with foo. Some shells sound a beep or show all the choices if more than one name matches. The user must then type more characters to identify the desired filename. Typing a t and pressing Tab again is enough to let the shell determine which filename is desired and fill in the rest. environment variables Another feature of the shell is the use of environment variables. Environment variables are a variable/key pair stored in the shell's environment. This environment can be read by any program invoked by the shell, and thus contains a lot of program configuration. provides a list of common environment variables and their meanings. Note that the names of environment variables are always in uppercase. Common Environment Variables Variable Description USER Current logged in user's name. PATH Colon-separated list of directories to search for binaries. DISPLAY Network name of the &xorg; display to connect to, if available. SHELL The current shell. TERM The name of the user's type of terminal. Used to determine the capabilities of the terminal. TERMCAP Database entry of the terminal escape codes to perform various terminal functions. OSTYPE Type of operating system. MACHTYPE The system's CPU architecture. EDITOR The user's preferred text editor. PAGER The user's preferred utility for viewing text one page at a time. MANPATH Colon-separated list of directories to search for manual pages.
Bourne shells How to set an environment variable differs between shells. In &man.tcsh.1; and &man.csh.1;, use setenv to set environment variables. In &man.sh.1; and bash, use export to set the current environment variables. This example sets the default EDITOR to /usr/local/bin/emacs for the &man.tcsh.1; shell: &prompt.user; setenv EDITOR /usr/local/bin/emacs The equivalent command for bash would be: &prompt.user; export EDITOR="/usr/local/bin/emacs" To expand an environment variable in order to see its current setting, type a $ character in front of its name on the command line. For example, echo $TERM displays the current $TERM setting. Shells treat special characters, known as meta-characters, as special representations of data. The most common meta-character is *, which represents any number of characters in a filename. Meta-characters can be used to perform filename globbing. For example, echo * is equivalent to ls because the shell takes all the files that match * and echo lists them on the command line. To prevent the shell from interpreting a special character, escape it from the shell by starting it with a backslash (\). For example, echo $TERM prints the terminal setting whereas echo \$TERM literally prints the string $TERM. Changing the Shell The easiest way to permanently change the default shell is to use chsh. Running this command will open the editor that is configured in the EDITOR environment variable, which by default is set to &man.vi.1;. Change the Shell: line to the full path of the new shell. Alternately, use chsh -s which will set the specified shell without opening an editor. For example, to change the shell to bash: &prompt.user; chsh -s /usr/local/bin/bash The new shell must be present in /etc/shells. If the shell was installed from the &os; Ports Collection as described in , it should be automatically added to this file. If it is missing, add it using this command, replacing the path with the path of the shell: &prompt.root; echo /usr/local/bin/bash >> /etc/shells Then, rerun &man.chsh.1;. Advanced Shell Techniques Tom Rhodes Written by The &unix; shell is not just a command interpreter, it acts as a powerful tool which allows users to execute commands, redirect their output, redirect their input and chain commands together to improve the final command output. When this functionality is mixed with built in commands, the user is provided with an environment that can maximize efficiency. Shell redirection is the action of sending the output or the input of a command into another command or into a file. To capture the output of the &man.ls.1; command, for example, into a file, simply redirect the output: &prompt.user; ls > directory_listing.txt The directory_listing.txt file will now contain the directory contents. Some commands allow you to read input in a similar one, such as &man.sort.1;. To sort this listing, redirect the input: &prompt.user; sort < directory_listing.txt The input will be sorted and placed on the screen. To redirect that input into another file, one could redirect the output of &man.sort.1; by mixing the direction: &prompt.user; sort < directory_listing.txt > sorted.txt In all of the previous examples, the commands are performing redirection using file descriptors. Every unix system has file descriptors; however, here we will focus on three, so named as Standard Input, Standard Output, and Standard Error. Each one has a purpose, where input could be a keyboard or a mouse, something that provides input. Output could be a screen or paper in a printer for example. And error would be anything that is used for diagnostic or error messages. All three are considered I/O based file descriptors and sometimes considered streams. Through the use of these descriptors, short named stdin, stdout, and stderr, the shell allows output and input to be passed around through various commands and redirected to or from a file. Another method of redirection is the pipe operator. The &unix; pipe operator, | allows the output of one command to be directly passed, or directed to another program. Basically a pipe will allow the standard output of a command to be passed as standard input to another command, for example: &prompt.user; cat directory_listing.txt | sort | less In that example, the contents of directory_listing.txt will be sorted and the output passed to &man.less.1;. This allows the user to scroll through the output at their own pace and prevent it from scrolling off the screen. Text Editors text editors editors Most &os; configuration is done by editing text files. Because of this, it is a good idea to become familiar with a text editor. &os; comes with a few as part of the base system, and many more are available in the Ports Collection. ee editors &man.ee.1; A simple editor to learn is &man.ee.1;, which stands for easy editor. To start this editor, type ee filename where filename is the name of the file to be edited. Once inside the editor, all of the commands for manipulating the editor's functions are listed at the top of the display. The caret (^) represents Ctrl, so ^e expands to Ctrl e . To leave &man.ee.1;, press Esc, then choose the leave editor option from the main menu. The editor will prompt to save any changes if the file has been modified. vi editors emacs &os; also comes with more powerful text editors, such as &man.vi.1;, as part of the base system. Other editors, like editors/emacs and editors/vim, are part of the &os; Ports Collection. These editors offer more functionality at the expense of being more complicated to learn. Learning a more powerful editor such as vim or Emacs can save more time in the long run. Many applications which modify files or require typed input will automatically open a text editor. To change the default editor, set the EDITOR environment variable as described in . Devices and Device Nodes A device is a term used mostly for hardware-related activities in a system, including disks, printers, graphics cards, and keyboards. When &os; boots, the majority of the boot messages refer to devices being detected. A copy of the boot messages are saved to /var/run/dmesg.boot. Each device has a device name and number. For example, ada0 is the first SATA hard drive, while kbd0 represents the keyboard. Most devices in a &os; must be accessed through special files called device nodes, which are located in /dev. Manual Pages manual pages The most comprehensive documentation on &os; is in the form of manual pages. Nearly every program on the system comes with a short reference manual explaining the basic operation and available arguments. These manuals can be viewed using man: &prompt.user; man command where command is the name of the command to learn about. For example, to learn more about &man.ls.1;, type: &prompt.user; man ls Manual pages are divided into sections which represent the type of topic. In &os;, the following sections are available: User commands. System calls and error numbers. Functions in the C libraries. Device drivers. File formats. Games and other diversions. Miscellaneous information. System maintenance and operation commands. System kernel interfaces. In some cases, the same topic may appear in more than one section of the online manual. For example, there is a chmod user command and a chmod() system call. To tell &man.man.1; which section to display, specify the section number: &prompt.user; man 1 chmod This will display the manual page for the user command &man.chmod.1;. References to a particular section of the online manual are traditionally placed in parenthesis in written documentation, so &man.chmod.1; refers to the user command and &man.chmod.2; refers to the system call. If the name of the manual page is unknown, use man -k to search for keywords in the manual page descriptions: &prompt.user; man -k mail This command displays a list of commands that have the keyword mail in their descriptions. This is equivalent to using &man.apropos.1;. To read the descriptions for all of the commands in /usr/bin, type: &prompt.user; cd /usr/bin &prompt.user; man -f * | more or &prompt.user; cd /usr/bin &prompt.user; whatis * |more GNU Info Files Free Software Foundation &os; includes several applications and utilities produced by the Free Software Foundation (FSF). In addition to manual pages, these programs may include hypertext documents called info files. These can be viewed using &man.info.1; or, if editors/emacs is installed, the info mode of emacs. To use &man.info.1;, type: &prompt.user; info For a brief introduction, type h. For a quick command reference, type ?. Index: head/en_US.ISO8859-1/books/handbook/dtrace/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/dtrace/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/dtrace/chapter.xml (revision 46052) @@ -1,358 +1,359 @@ + xml:id="dtrace"> + &dtrace; TomRhodesWritten by Synopsis &dtrace; &dtrace; support &dtrace; &dtrace;, also known as Dynamic Tracing, was developed by &sun; as a tool for locating performance bottlenecks in production and pre-production systems. In addition to diagnosing performance problems, &dtrace; can be used to help investigate and debug unexpected behavior in both the &os; kernel and in userland programs. &dtrace; is a remarkable profiling tool, with an impressive array of features for diagnosing system issues. It may also be used to run pre-written scripts to take advantage of its capabilities. Users can author their own utilities using the &dtrace; D Language, allowing them to customize their profiling based on specific needs. The &os; implementation provides full support for kernel &dtrace; and experimental support for userland &dtrace;. Userland &dtrace; allows users to perform function boundary tracing for userland programs using the pid provider, and to insert static probes into userland programs for later tracing. Some ports, such as databases/postgres-server and lang/php5 have a &dtrace; option to enable static probes. &os; 10.0-RELEASE has reasonably good userland &dtrace; support, but it is not considered production ready. In particular, it is possible to crash traced programs. After reading this chapter, you will know: What &dtrace; is and what features it provides. Differences between the &solaris; &dtrace; implementation and the one provided by &os;. How to enable and use &dtrace; on &os;. Before reading this chapter, you should: Understand &unix; and &os; basics (). Have some familiarity with security and how it pertains to &os; (). Implementation Differences While the &dtrace; in &os; is similar to that found in &solaris;, differences do exist. The primary difference is that in &os;, &dtrace; is implemented as a set of kernel modules and &dtrace; can not be used until the modules are loaded. To load all of the necessary modules: &prompt.root; kldload dtraceall Beginning with &os; 10.0-RELEASE, the modules are automatically loaded when dtrace is run. &os; uses the DDB_CTF kernel option to enable support for loading CTF data from kernel modules and the kernel itself. CTF is the &solaris; Compact C Type Format which encapsulates a reduced form of debugging information similar to DWARF and the venerable stabs. CTF data is added to binaries by the ctfconvert and ctfmerge build tools. The ctfconvert utility parses DWARF ELF debug sections created by the compiler and ctfmerge merges CTF ELF sections from objects into either executables or shared libraries. Some different providers exist for &os; than for &solaris;. Most notable is the dtmalloc provider, which allows tracing malloc() by type in the &os; kernel. Some of the providers found in &solaris;, such as cpc and mib, are not present in &os;. These may appear in future versions of &os;. Moreover, some of the providers available in both operating systems are not compatible, in the sense that their probes have different argument types. Thus, D scripts written on &solaris; may or may not work unmodified on &os;, and vice versa. Due to security differences, only root may use &dtrace; on &os;. &solaris; has a few low level security checks which do not yet exist in &os;. As such, the /dev/dtrace/dtrace is strictly limited to root. &dtrace; falls under the Common Development and Distribution License (CDDL) license. To view this license on &os;, see /usr/src/cddl/contrib/opensolaris/OPENSOLARIS.LICENSE or view it online at http://opensource.org/licenses/CDDL-1.0. While a &os; kernel with &dtrace; support is BSD licensed, the CDDL is used when the modules are distributed in binary form or the binaries are loaded. Enabling &dtrace; Support In &os; 9.2 and 10.0, &dtrace; support is built into the GENERIC kernel. Users of earlier versions of &os; or who prefer to statically compile in &dtrace; support should add the following lines to a custom kernel configuration file and recompile the kernel using the instructions in : options KDTRACE_HOOKS options DDB_CTF options DEBUG=-g Users of the AMD64 architecture should also add this line: options KDTRACE_FRAME This option provides support for FBT. While &dtrace; will work without this option, there will be limited support for function boundary tracing. Once the &os; system has rebooted into the new kernel, or the &dtrace; kernel modules have been loaded using kldload dtraceall, the system will need support for the Korn shell as the &dtrace; Toolkit has several utilities written in ksh. Make sure that the shells/ksh93 package or port is installed. It is also possible to run these tools under shells/pdksh or shells/mksh. Finally, install the current &dtrace; Toolkit, a collection of ready-made scripts for collecting system information. There are scripts to check open files, memory, CPU usage, and a lot more. &os; 10 installs a few of these scripts into /usr/share/dtrace. On other &os; versions, or to install the full &dtrace; Toolkit, use the sysutils/DTraceToolkit package or port. The scripts found in /usr/share/dtrace have been specifically ported to &os;. Not all of the scripts found in the &dtrace; Toolkit will work as-is on &os; and some scripts may require some effort in order for them to work on &os;. The &dtrace; Toolkit includes many scripts in the special language of &dtrace;. This language is called the D language and it is very similar to C++. An in depth discussion of the language is beyond the scope of this document. It is extensively discussed at http://wikis.oracle.com/display/DTrace/Documentation. Using &dtrace; &dtrace; scripts consist of a list of one or more probes, or instrumentation points, where each probe is associated with an action. Whenever the condition for a probe is met, the associated action is executed. For example, an action may occur when a file is opened, a process is started, or a line of code is executed. The action might be to log some information or to modify context variables. The reading and writing of context variables allows probes to share information and to cooperatively analyze the correlation of different events. To view all probes, the administrator can execute the following command: &prompt.root; dtrace -l | more Each probe has an ID, a PROVIDER (dtrace or fbt), a MODULE, and a FUNCTION NAME. Refer to &man.dtrace.1; for more information about this command. The examples in this section provide an overview of how to use two of the fully supported scripts from the &dtrace; Toolkit: the hotkernel and procsystime scripts. The hotkernel script is designed to identify which function is using the most kernel time. It will produce output similar to the following: &prompt.root; cd /usr/share/dtrace/toolkit &prompt.root; ./hotkernel Sampling... Hit Ctrl-C to end. As instructed, use the CtrlC key combination to stop the process. Upon termination, the script will display a list of kernel functions and timing information, sorting the output in increasing order of time: kernel`_thread_lock_flags 2 0.0% 0xc1097063 2 0.0% kernel`sched_userret 2 0.0% kernel`kern_select 2 0.0% kernel`generic_copyin 3 0.0% kernel`_mtx_assert 3 0.0% kernel`vm_fault 3 0.0% kernel`sopoll_generic 3 0.0% kernel`fixup_filename 4 0.0% kernel`_isitmyx 4 0.0% kernel`find_instance 4 0.0% kernel`_mtx_unlock_flags 5 0.0% kernel`syscall 5 0.0% kernel`DELAY 5 0.0% 0xc108a253 6 0.0% kernel`witness_lock 7 0.0% kernel`read_aux_data_no_wait 7 0.0% kernel`Xint0x80_syscall 7 0.0% kernel`witness_checkorder 7 0.0% kernel`sse2_pagezero 8 0.0% kernel`strncmp 9 0.0% kernel`spinlock_exit 10 0.0% kernel`_mtx_lock_flags 11 0.0% kernel`witness_unlock 15 0.0% kernel`sched_idletd 137 0.3% 0xc10981a5 42139 99.3% This script will also work with kernel modules. To use this feature, run the script with : &prompt.root; ./hotkernel -m Sampling... Hit Ctrl-C to end. ^C MODULE COUNT PCNT 0xc107882e 1 0.0% 0xc10e6aa4 1 0.0% 0xc1076983 1 0.0% 0xc109708a 1 0.0% 0xc1075a5d 1 0.0% 0xc1077325 1 0.0% 0xc108a245 1 0.0% 0xc107730d 1 0.0% 0xc1097063 2 0.0% 0xc108a253 73 0.0% kernel 874 0.4% 0xc10981a5 213781 99.6% The procsystime script captures and prints the system call time usage for a given process ID (PID) or process name. In the following example, a new instance of /bin/csh was spawned. Then, procsystime was executed and remained waiting while a few commands were typed on the other incarnation of csh. These are the results of this test: &prompt.root; ./procsystime -n csh Tracing... Hit Ctrl-C to end... ^C Elapsed Times for processes csh, SYSCALL TIME (ns) getpid 6131 sigreturn 8121 close 19127 fcntl 19959 dup 26955 setpgid 28070 stat 31899 setitimer 40938 wait4 62717 sigaction 67372 sigprocmask 119091 gettimeofday 183710 write 263242 execve 492547 ioctl 770073 vfork 3258923 sigsuspend 6985124 read 3988049784 As shown, the read() system call used the most time in nanoseconds while the getpid() system call used the least amount of time. Index: head/en_US.ISO8859-1/books/handbook/filesystems/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/filesystems/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/filesystems/chapter.xml (revision 46052) @@ -1,218 +1,219 @@ + xml:id="filesystems"> + Other File Systems TomRhodesWritten by Synopsis File Systems File Systems Support File Systems File systems are an integral part of any operating system. They allow users to upload and store files, provide access to data, and make hard drives useful. Different operating systems differ in their native file system. Traditionally, the native &os; file system has been the Unix File System UFS which has been modernized as UFS2. Since &os; 7.0, the Z File System (ZFS) is also available as a native file system. See for more information. In addition to its native file systems, &os; supports a multitude of other file systems so that data from other operating systems can be accessed locally, such as data stored on locally attached USB storage devices, flash drives, and hard disks. This includes support for the &linux; Extended File System (EXT) and the Reiser file system. There are different levels of &os; support for the various file systems. Some require a kernel module to be loaded and others may require a toolset to be installed. Some non-native file system support is full read-write while others are read-only. After reading this chapter, you will know: The difference between native and supported file systems. Which file systems are supported by &os;. How to enable, configure, access, and make use of non-native file systems. Before reading this chapter, you should: Understand &unix; and &os; basics. Be familiar with the basics of kernel configuration and compilation. Feel comfortable installing software in &os;. Have some familiarity with disks, storage, and device names in &os;. &linux; File Systems &os; provides built-in support for several &linux; file systems. This section demonstrates how to load support for and how to mount the supported &linux; file systems. <acronym>ext2</acronym> Kernel support for ext2 file systems has been available since &os; 2.2. In &os; 8.x and earlier, the code is licensed under the GPL. Since &os; 9.0, the code has been rewritten and is now BSD licensed. The &man.ext2fs.5; driver allows the &os; kernel to both read and write to ext2 file systems. This driver can also be used to access ext3 and ext4 file systems. However, ext3 journaling, extended attributes, and inodes greater than 128-bytes are not supported. Support for ext4 is read-only. To access an ext file system, first load the kernel loadable module: &prompt.root; kldload ext2fs Then, mount the ext volume by specifying its &os; partition name and an existing mount point. This example mounts /dev/ad1s1 on /mnt: &prompt.root; mount -t ext2fs /dev/ad1s1 /mnt XFS A &os; kernel can be configured to provide read-only support for XFS file systems. To compile in XFS support, add the following option to a custom kernel configuration file and recompile the kernel using the instructions in : options XFS Then, to mount an XFS volume located on /dev/ad1s1: &prompt.root; mount -t xfs /dev/ad1s1 /mnt The sysutils/xfsprogs package or port provides additional utilities, with man pages, for using, analyzing, and repairing XFS file systems. ReiserFS &os; provides read-only support for The Reiser file system, ReiserFS. To load the &man.reiserfs.5; driver: &prompt.root; kldload reiserfs Then, to mount a ReiserFS volume located on /dev/ad1s1: &prompt.root; mount -t reiserfs /dev/ad1s1 /mnt Index: head/en_US.ISO8859-1/books/handbook/install/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/install/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/install/chapter.xml (revision 46052) @@ -1,4624 +1,4625 @@ + xml:id="install"> + Installing &os; 8.<replaceable>X</replaceable> JimMockRestructured, reorganized, and parts rewritten by RandyPrattThe sysinstall walkthrough, screenshots, and general copy by Synopsis installation &os; provides a text-based, easy to use installation program. &os; 9.0-RELEASE and later use the installation program known as &man.bsdinstall.8; while &os; 8.X uses &man.sysinstall.8;. This chapter describes how to use &man.sysinstall.8;. The use of &man.bsdinstall.8; is covered in . After reading this chapter, you will know: How to create the &os; installation media. How &os; refers to and subdivides hard disks. How to start &man.sysinstall.8;. The questions &man.sysinstall.8; asks, what they mean, and how to answer them. Before reading this chapter, you should: Read the supported hardware list that shipped with the version of &os; to install, and verify that the system's hardware is supported. In general, these installation instructions are written for the &i386; and &os;/&arch.amd64; architectures. Where applicable, instructions specific to other platforms will be listed. There may be minor differences between the installer and what is shown here. This chapter should be used as a general guide rather than a literal installation manual. Hardware Requirements Minimal Configuration The minimal configuration to install &os; varies with the &os; version and the hardware architecture. A summary of this information is given in the following sections. Depending on the method chosen to install &os;, a floppy drive, CDROM drive, or network adapter may be needed. Instructions on how to prepare the installation media can be found in . &os;/&arch.i386; and &os;/&arch.pc98; Both &os;/&arch.i386; and &os;/&arch.pc98; require a 486 or better processor, at least 24 MB of RAM, and at least 150 MB of free hard drive space for the most minimal installation. In the case of older hardware, installing more RAM and more hard drive space is often more important than a faster processor. &os;/&arch.amd64; There are two classes of processors capable of running &os;/&arch.amd64;. The first are AMD64 processors, including the &amd.athlon;64, &amd.athlon;64-FX, and &amd.opteron; or better processors. The second class of processors includes those using the &intel; EM64T architecture. Examples of these processors include the &intel; &core; 2 Duo, Quad, Extreme processor families, and the &intel; &xeon; 3000, 5000, and 7000 sequences of processors. If the machine is based on an nVidia nForce3 Pro-150, the BIOS setup must be used to disable the IO APIC. If this option does not exist, disable ACPI instead as there are bugs in the Pro-150 chipset. &os;/&arch.sparc64; To install &os;/&arch.sparc64;, use a supported platform (see ). A dedicated disk is needed for &os;/&arch.sparc64; as it is not possible to share a disk with another operating system at this time. Supported Hardware A list of supported hardware is provided with each &os; release in the &os; Hardware Notes. This document can usually be found in a file named HARDWARE.TXT, in the top-level directory of a CDROM or FTP distribution, or in &man.sysinstall.8;'s documentation menu. It lists, for a given architecture, which hardware devices are known to be supported by each release of &os;. Copies of the supported hardware list for various releases and architectures can also be found on the Release Information page of the &os; website. Pre-installation Tasks Inventory the Computer Before installing &os; it is recommended to inventory the components in the computer. The &os; installation routines will show components such as hard disks, network cards, and CDROM drives with their model number and manufacturer. &os; will also attempt to determine the correct configuration for these devices, including information about IRQ and I/O port usage. Due to the vagaries of computer hardware, this process is not always completely successful, and &os; may need some manual configuration. If another operating system is already installed, use the facilities provided by that operating systems to view the hardware configuration. If the settings of an expansion card are not obvious, check if they are printed on the card itself. Popular IRQ numbers are 3, 5, and 7, and I/O port addresses are normally written as hexadecimal numbers, such as 0x330. It is recommended to print or write down this information before installing &os;. It may help to use a table, as seen in this example: Sample Device Inventory Device Name IRQ I/O port(s) Notes First hard disk N/A N/A 40 GB, made by Seagate, first IDE master CDROM N/A N/A First IDE slave Second hard disk N/A N/A 20 GB, made by IBM, second IDE master First IDE controller 14 0x1f0 Network card N/A N/A &intel; 10/100 Modem N/A N/A &tm.3com; 56K faxmodem, on COM1 …
Once the inventory of the components in the computer is complete, check if it matches the hardware requirements of the &os; release to install. Make a Backup If the computer contains valuable data, ensure it is backed up, and that the backup has been tested before installing &os;. The &os; installer will prompt before writing any data to disk, but once that process has started, it cannot be undone. Decide Where to Install &os; If &os; is to be installed on the entire hard disk, skip this section. However, if &os; will co-exist with other operating systems, a rough understanding of how data is laid out on the disk is useful. Disk Layouts for &os;/&arch.i386; A PC disk can be divided into discrete chunks known as partitions. Since &os; also has partitions, naming can quickly become confusing. Therefore, these disk chunks are referred to as slices in &os;. For example, the &os; version of &man.fdisk.8; refers to slices instead of partitions. By design, the PC only supports four partitions per disk. These partitions are called primary partitions. To work around this limitation and allow more than four partitions, a new partition type was created, the extended partition. A disk may contain only one extended partition. Special partitions, called logical partitions, can be created inside this extended partition. Each partition has a partition ID, which is a number used to identify the type of data on the partition. &os; partitions have the partition ID of 165. In general, each operating system will identify partitions in a particular way. For example, &windows;, assigns each primary and logical partition a drive letter, starting with C:. &os; must be installed into a primary partition. If there are multiple disks, a &os; partition can be created on all, or some, of them. When &os; is installed, at least one partition must be available. This might be a blank partition or it might be an existing partition whose data can be overwritten. If all the partitions on all the disks are in use, free one of them for &os; using the tools provided by an existing operating system, such as &windows; fdisk. If there is a spare partition, use that. If it is too small, shrink one or more existing partitions to create more available space. A minimal installation of &os; takes as little as 100 MB of disk space. However, that is a very minimal install, leaving almost no space for files. A more realistic minimum is 250 MB without a graphical environment, and 350 MB or more for a graphical user interface. If other third-party software will be installed, even more space is needed. You can use a tool such as GParted to resize your partitions and make space for &os;. GParted is known to work on NTFS and is available on a number of Live CD Linux distributions, such as SystemRescueCD. Incorrect use of a shrinking tool can delete the data on the disk. Always have a recent, working backup before using this type of tool. Using an Existing Partition Unchanged Consider a computer with a single 4 GB disk that already has a version of &windows; installed, where the disk has been split into two drive letters, C: and D:, each of which is 2 GB in size. There is 1 GB of data on C:, and 0.5 GB of data on D:. This disk has two partitions, one per drive letter. Copy all existing data from D: to C:, which will free up the second partition, ready for &os;. Shrinking an Existing Partition Consider a computer with a single 4 GB disk that already has a version of &windows; installed. When &windows; was installed, it created one large partition, a C: drive that is 4 GB in size. Currently, 1.5 GB of space is used, and &os; should have 2 GB of space. In order to install &os;, either: Backup the &windows; data and then reinstall &windows;, asking for a 2 GB partition at install time. Use one of the tools described above to shrink your &windows; partition. Collect the Network Configuration Details Before installing from an FTP site or an NFS server, make note of the network configuration. The installer will prompt for this information so that it can connect to the network to complete the installation. Connecting to an Ethernet Network or Cable/DSL Modem If using an Ethernet network or an Internet connection using an Ethernet adapter via cable or DSL, the following information is needed: IP address IP address of the default gateway Hostname DNS server IP addresses Subnet Mask If this information is unknown, ask the system administrator or service provider. Make note if this information is assigned automatically using DHCP. Connecting Using a Modem If using a dialup modem, &os; can still be installed over the Internet, it will just take a very long time. You will need to know: The phone number to dial the Internet Service Provider (ISP) The COM: port the modem is connected to The username and password for the ISP account Check for &os; Errata Although the &os; Project strives to ensure that each release of &os; is as stable as possible, bugs do occasionally creep into the process. On rare occasions those bugs affect the installation process. As these problems are discovered and fixed, they are noted in the &os; Errata, which is found on the &os; website. Check the errata before installing to make sure that there are no late-breaking problems to be aware of. Information about all releases, including the errata for each release, can be found on the release information section of the &os; website. Obtain the &os; Installation Files The &os; installer can install &os; from files located in any of the following places: Local Media A CDROM or DVD A USB Memory Stick A &ms-dos; partition on the same computer Floppy disks (&os;/&arch.pc98; only) Network An FTP site through a firewall or using an HTTP proxy An NFS server A dedicated parallel or serial connection If installing from a purchased &os; CD/DVD, skip ahead to . To obtain the &os; installation files, skip ahead to which explains how to prepare the installation media. After reading that section, come back here and read on to . Prepare the Boot Media The &os; installation process is started by booting the computer into the &os; installer. It is not a program that can be run within another operating system. The computer normally boots using the operating system installed on the hard disk, but it can also be configured to boot from a CDROM or from a USB disk. If installing from a CD/DVD to a computer whose BIOS supports booting from the CD/DVD, skip this section. The &os; CD/DVD images are bootable and can be used to install &os; without any other special preparation. To create a bootable memory stick, follow these steps: Acquire the Memory Stick Image Memory stick images for &os; 8.X can be downloaded from the ISO-IMAGES/ directory at ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/arch/ISO-IMAGES/version/&os;-version-RELEASE-arch-memstick.img. Replace arch and version with the architecture and the version number to install. For example, the memory stick images for &os;/&arch.i386; &rel2.current;-RELEASE are available from ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/&arch.i386;/ISO-IMAGES/&rel2.current;/&os;-&rel2.current;-RELEASE-&arch.i386;-memstick.img. A different directory path is used for &os; 9.0-RELEASE and later versions. How to download and install &os; 9.X is covered in . The memory stick image has a .img extension. The ISO-IMAGES/ directory contains a number of different images and the one to use depends on the version of &os; and the type of media supported by the hardware being installed to. Before proceeding, back up the data on the USB stick, as this procedure will erase it. Write the Image File to the Memory Stick Using &os; to Write the Image The example below lists /dev/da0 as the target device where the image will be written. Be very careful that you have the correct device as the output target, or you may destroy your existing data. Writing the Image with &man.dd.1; The .img file is not a regular file that can just be copied to the memory stick. It is an image of the complete contents of the disk. This means that &man.dd.1; must be used to write the image directly to the disk: &prompt.root; dd if=&os;-&rel2.current;-RELEASE-&arch.i386;-memstick.img of=/dev/da0 bs=64k If an Operation not permitted error is displayed, make certain that the target device is not in use, mounted, or being automounted by another program. Then try again. Using &windows; to Write the Image Make sure to use the correct drive letter as the output target, as this command will overwrite and destroy any existing data on the specified device. Obtaining <application>Image Writer for Windows</application> Image Writer for Windows is a free application that can correctly write an image file to a memory stick. Download it from https://launchpad.net/win32-image-writer/ and extract it into a folder. Writing the Image with Image Writer Double-click the Win32DiskImager icon to start the program. Verify that the drive letter shown under Device is the drive with the memory stick. Click the folder icon and select the image to be written to the memory stick. Click Save to accept the image file name. Verify that everything is correct, and that no folders on the memory stick are open in other windows. Finally, click Write to write the image file to the drive. To create the boot floppy images for a &os;/&arch.pc98; installation, follow these steps: Acquire the Boot Floppy Images The &os;/&arch.pc98; boot disks can be downloaded from the floppies directory, ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/pc98/version-RELEASE/floppies/. Replace version with the version number to install. The floppy images have a .flp extension. floppies/ contains a number of different images. Download boot.flp as well as the number of files associated with the type of installation, such as kern.small* or kern*. The FTP program must use binary mode to download these disk images. Some web browsers use text or ASCII mode, which will be apparent if the disks are not bootable. Prepare the Floppy Disks Prepare one floppy disk per downloaded image file. It is imperative that these disks are free from defects. The easiest way to test this is to reformat the disks. Do not trust pre-formatted floppies. The format utility in &windows; will not tell about the presence of bad blocks, it simply marks them as bad and ignores them. It is advised to use brand new floppies. If the installer crashes, freezes, or otherwise misbehaves, one of the first things to suspect is the floppies. Write the floppy image files to new disks and try again. Write the Image Files to the Floppy Disks The .flp files are not regular files that can be copied to the disk. They are images of the complete contents of the disk. Specific tools must be used to write the images directly to the disk. DOS &os; provides a tool called rawrite for creating the floppies on a computer running &windows;. This tool can be downloaded from ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/pc98/ version-RELEASE/tools/ on the &os; FTP site. Download this tool, insert a floppy, then specify the filename to write to the floppy drive: C:\> rawrite boot.flp A: Repeat this command for each .flp file, replacing the floppy disk each time, being sure to label the disks with the name of the file. Adjust the command line as necessary, depending on where the .flp files are located. When writing the floppies on a &unix;-like system, such as another &os; system, use &man.dd.1; to write the image files directly to disk. On &os;, run: &prompt.root; dd if=boot.flp of=/dev/fd0 On &os;, /dev/fd0 refers to the first floppy disk. Other &unix; variants might have different names for the floppy disk device, so check the documentation for the system as necessary. You are now ready to start installing &os;. Starting the Installation By default, the installer will not make any changes to the disk(s) until after the following message: Last Chance: Are you SURE you want continue the installation? If you're running this on a disk with data you wish to save then WE STRONGLY ENCOURAGE YOU TO MAKE PROPER BACKUPS before proceeding! We can take no responsibility for lost disk contents! The install can be exited at any time prior to this final warning without changing the contents of the hard drive. If there is a concern that something is configured incorrectly, turn the computer off before this point, and no damage will be done. Booting Booting for the &i386; Turn on the computer. As it starts it should display an option to enter the system set up menu, or BIOS, commonly reached by keys like F2, F10, Del, or Alt S . Use whichever keystroke is indicated on screen. In some cases the computer may display a graphic while it starts. Typically, pressing Esc will dismiss the graphic and display the boot messages. Find the setting that controls which devices the system boots from. This is usually labeled as the Boot Order and commonly shown as a list of devices, such as Floppy, CDROM, First Hard Disk, and so on. If booting from the CD/DVD, make sure that the CDROM drive is selected. If booting from a USB disk, make sure that it is selected instead. When in doubt, consult the manual that came with the computer or its motherboard. Make the change, then save and exit. The computer should now restart. If using a prepared a bootable USB stick, as described in , plug in the USB stick before turning on the computer. If booting from CD/DVD, turn on the computer, and insert the CD/DVD at the first opportunity. For &os;/&arch.pc98;, installation boot floppies are available and can be prepared as described in . The first floppy disc will contain boot.flp. Put this floppy in the floppy drive to boot into the installer. If the computer starts up as normal and loads the existing operating system, then either: The disks were not inserted early enough in the boot process. Leave them in, and try restarting the computer. The BIOS changes did not work correctly. Redo that step until the right option is selected. That particular BIOS does not support booting from the desired media. &os; will start to boot. If booting from CD/DVD, messages will be displayed, similar to these: Booting from CD-Rom... 645MB medium detected CD Loader 1.2 Building the boot loader arguments Looking up /BOOT/LOADER... Found Relocating the loader and the BTX Starting the BTX loader BTX loader 1.00 BTX version is 1.02 Consoles: internal video/keyboard BIOS CD is cd0 BIOS drive C: is disk0 BIOS drive D: is disk1 BIOS 636kB/261056kB available memory FreeBSD/i386 bootstrap loader, Revision 1.1 Loading /boot/defaults/loader.conf /boot/kernel/kernel text=0x64daa0 data=0xa4e80+0xa9e40 syms=[0x4+0x6cac0+0x4+0x88e9d] \ If booting from floppy disc, a display similar to this will be shown: Booting from Floppy... Uncompressing ... done BTX loader 1.00 BTX version is 1.01 Console: internal video/keyboard BIOS drive A: is disk0 BIOS drive C: is disk1 BIOS 639kB/261120kB available memory FreeBSD/i386 bootstrap loader, Revision 1.1 Loading /boot/defaults/loader.conf /kernel text=0x277391 data=0x3268c+0x332a8 | Insert disk labelled "Kernel floppy 1" and press any key... Remove the boot.flp floppy, insert the next floppy, and press Enter. When prompted, insert the other disks as required. The boot process will then display the &os; boot loader menu:
&os; Boot Loader Menu
Either wait ten seconds, or press Enter. Booting for &sparc64; Most &sparc64; systems are set to boot automatically from disk. To install &os;, boot over the network or from a CD/DVD and wait until the boot message appears. The message depends on the model, but should look similar to: Sun Blade 100 (UltraSPARC-IIe), Keyboard Present Copyright 1998-2001 Sun Microsystems, Inc. All rights reserved. OpenBoot 4.2, 128 MB memory installed, Serial #51090132. Ethernet address 0:3:ba:b:92:d4, Host ID: 830b92d4. If the system proceeds to boot from disk, press L1A or StopA on the keyboard, or send a BREAK over the serial console using ~# in &man.tip.1; or &man.cu.1; to get to the PROM prompt. It looks like this: ok ok {0} This is the prompt used on systems with just one CPU. This is the prompt used on SMP systems and the digit indicates the number of the active CPU. At this point, place the CD/DVD into the drive and from the PROM prompt, type boot cdrom. Reviewing the Device Probe Results The last few hundred lines that have been displayed on screen are stored and can be reviewed. To review this buffer, press Scroll Lock to turn on scrolling in the display. Use the arrow keys or PageUp and PageDown to view the results. Press Scroll Lock again to stop scrolling. Do this now, to review the text that scrolled off the screen when the kernel was carrying out the device probes. Text similar to will be displayed, although it will differ depending on the devices in the computer.
Typical Device Probe Results avail memory = 253050880 (247120K bytes) Preloaded elf kernel "kernel" at 0xc0817000. Preloaded mfs_root "/mfsroot" at 0xc0817084. md0: Preloaded image </mfsroot> 4423680 bytes at 0xc03ddcd4 md1: Malloc disk Using $PIR table, 4 entries at 0xc00fde60 npx0: <math processor> on motherboard npx0: INT 16 interface pcib0: <Host to PCI bridge> on motherboard pci0: <PCI bus> on pcib0 pcib1:<VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 on pci0 pci1: <PCI bus> on pcib1 pci1: <Matrox MGA G200 AGP graphics accelerator> at 0.0 irq 11 isab0: <VIA 82C586 PCI-ISA bridge> at device 7.0 on pci0 isa0: <iSA bus> on isab0 atapci0: <VIA 82C586 ATA33 controller> port 0xe000-0xe00f at device 7.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 uhci0 <VIA 83C572 USB controller> port 0xe400-0xe41f irq 10 at device 7.2 on pci 0 usb0: <VIA 83572 USB controller> on uhci0 usb0: USB revision 1.0 uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr1 uhub0: 2 ports with 2 removable, self powered pci0: <unknown card> (vendor=0x1106, dev=0x3040) at 7.3 dc0: <ADMtek AN985 10/100BaseTX> port 0xe800-0xe8ff mem 0xdb000000-0xeb0003ff ir q 11 at device 8.0 on pci0 dc0: Ethernet address: 00:04:5a:74:6b:b5 miibus0: <MII bus> on dc0 ukphy0: <Generic IEEE 802.3u media interface> on miibus0 ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto ed0: <NE2000 PCI Ethernet (RealTek 8029)> port 0xec00-0xec1f irq 9 at device 10. 0 on pci0 ed0 address 52:54:05:de:73:1b, type NE2000 (16 bit) isa0: too many dependant configs (8) isa0: unexpected small tag 14 orm0: <Option ROM> at iomem 0xc0000-0xc7fff on isa0 fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: <1440-KB 3.5” drive> on fdc0 drive 0 atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0 atkbd0: <AT Keyboard> flags 0x1 irq1 on atkbdc0 kbd0 at atkbd0 psm0: <PS/2 Mouse> irq 12 on atkbdc0 psm0: model Generic PS/@ mouse, device ID 0 vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0 sc0: <System console> at flags 0x100 on isa0 sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 pppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/15 bytes threshold plip0: <PLIP network interface> on ppbus0 ad0: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata0-master UDMA33 acd0: CD-RW <LITE-ON LTR-1210B> at ata1-slave PIO4 Mounting root from ufs:/dev/md0c /stand/sysinstall running as init on vty0
Check the probe results carefully to make sure that &os; found all the devices. If a device was not found, it will not be listed. A custom kernel can be used to add in support for devices which are not in the GENERIC kernel. After the device probe, the menu shown in will be displayed. Use the arrow key to choose a country, region, or group. Then press Enter to set the country.
Selecting Country Menu
If United States is selected as the country, the standard American keyboard map will be used. If a different country is chosen, the following menu will be displayed. Use the arrow keys to choose the correct keyboard map and press Enter.
Selecting Keyboard Menu
After the country selection, the &man.sysinstall.8; main menu will display. Introducing &man.sysinstall.8; The &os; 8.X installer, &man.sysinstall.8;, is console based and is divided into a number of menus and screens that can be used to configure and control the installation process. This menu system is controlled by the arrow keys, Enter, Tab, Space, and other keys. To view a detailed description of these keys and what they do, ensure that the Usage entry is highlighted and that the [Select] button is selected, as shown in , then press Enter. The instructions for using the menu system will be displayed. After reviewing them, press Enter to return to the Main Menu.
Selecting Usage from Sysinstall Main Menu
Selecting the Documentation Menu From the Main Menu, select Doc with the arrow keys and press Enter.
Selecting Documentation Menu
This will display the Documentation Menu.
Sysinstall Documentation Menu
It is important to read the documents provided. To view a document, select it with the arrow keys and press Enter. When finished reading a document, press Enter to return to the Documentation Menu. To return to the Main Installation Menu, select Exit with the arrow keys and press Enter. Selecting the Keymap Menu To change the keyboard mapping, use the arrow keys to select Keymap from the menu and press Enter. This is only required when using a non-standard or non-US keyboard.
Sysinstall Main Menu
A different keyboard mapping may be chosen by selecting the menu item using the up and down arrow keys and pressing Space. Pressing Space again will unselect the item. When finished, choose the &gui.ok; using the arrow keys and press Enter. Only a partial list is shown in this screen representation. Selecting &gui.cancel; by pressing Tab will use the default keymap and return to the Main Install Menu.
Sysinstall Keymap Menu
Installation Options Screen Select Options and press Enter.
Sysinstall Main Menu
Sysinstall Options
The default values are usually fine for most users and do not need to be changed. The release name will vary according to the version being installed. The description of the selected item will appear at the bottom of the screen highlighted in blue. Notice that one of the options is Use Defaults to reset all values to startup defaults. Press F1 to read the help screen about the various options. Press Q to return to the Main Install menu. Begin a Standard Installation The Standard installation is the option recommended for those new to &unix; or &os;. Use the arrow keys to select Standard and then press Enter to start the installation.
Begin Standard Installation
Allocating Disk Space The first task is to allocate disk space for &os;, and label that space so that &man.sysinstall.8; can prepare it. In order to do this you need to know how &os; expects to find information on the disk. BIOS Drive Numbering Before installing and configuring &os; it is important to be aware how &os; deals with BIOS drive mappings. MS-DOS Microsoft Windows In a PC running a BIOS-dependent operating system such as µsoft.windows;, the BIOS is able to abstract the normal disk drive order and the operating system goes along with the change. This allows the user to boot from a disk drive other than the "primary master". This is especially convenient for users buy an identical second hard drive, and perform routine copies of the first drive to the second drive. If the first drive fails, is attacked by a virus, or is scribbled upon by an operating system defect, they can easily recover by instructing the BIOS to logically swap the drives. It is like switching the cables on the drives, without having to open the case. SCSI BIOS Systems with SCSI controllers often include BIOS extensions which allow the SCSI drives to be re-ordered in a similar fashion for up to seven drives. A user who is accustomed to taking advantage of these features may become surprised when the results with &os; are not as expected. &os; does not use the BIOS, and does not know the logical BIOS drive mapping. This can lead to perplexing situations, especially when drives are physically identical in geometry and have been made as data clones of one another. When using &os;, always restore the BIOS to natural drive numbering before installing &os;, and then leave it that way. If drives need to be switched around, take the time to open the case and move the jumpers and cables. An Illustration from the Files of Bill and Fred's Exceptional Adventures: Bill breaks-down an older Wintel box to make another &os; box for Fred. Bill installs a single SCSI drive as SCSI unit zero and installs &os; on it. Fred begins using the system, but after several days notices that the older SCSI drive is reporting numerous errors. To address the situation, Bill grabs an identical SCSI drive and installs this drive as SCSI unit four and makes an image copy from drive zero to drive four. Now that the new drive is installed and functioning, Bill decides to start using it, so he uses features in the SCSI BIOS to re-order the disk drives so that the system boots from SCSI unit four. &os; boots and runs just fine. Fred continues his work and soon decides that it is time to upgrade to a newer version of &os;. Bill removes SCSI unit zero because it was a bit flaky and replaces it with another identical disk drive. Bill then installs the new version of &os; onto the new SCSI unit zero and the installation goes well. Fred uses the new version of &os; for a few days, and certifies that it is good enough for use in the engineering department. It is time to copy all of his work from the old version, so Fred mounts SCSI unit four which should contain the latest copy of the older &os; version. Fred is dismayed to find that none of his work is present on SCSI unit four. It turns out that when Bill made an image copy of the original SCSI unit zero onto SCSI unit four, unit four became the new clone. When Bill re-ordered the SCSI BIOS so that he could boot from SCSI unit four, &os; was still running on SCSI unit zero. Making this kind of BIOS change causes some or all of the boot and loader code to be fetched from the selected BIOS drive. But when the &os; kernel drivers take over, the BIOS drive numbering is ignored, and &os; transitions back to normal drive numbering. In this example, the system continued to operate on the original SCSI unit zero, and all of Fred's data was there, not on SCSI unit four. The fact that the system appeared to be running on SCSI unit four was simply an artifact of human expectations. Fortunately, the older SCSI unit zero was retrieved and all of Fred's work was restored. Although SCSI drives were used in this illustration, the concepts apply equally to IDE drives. Creating Slices Using FDisk After choosing to begin a standard installation in &man.sysinstall.8;, this message will appear: Message In the next menu, you will need to set up a DOS-style ("fdisk") partitioning scheme for your hard disk. If you simply wish to devote all disk space to FreeBSD (overwriting anything else that might be on the disk(s) selected) then use the (A)ll command to select the default partitioning scheme followed by a (Q)uit. If you wish to allocate only free space to FreeBSD, move to a partition marked "unused" and use the (C)reate command. [ OK ] [ Press enter or space ] Press Enter and a list of all the hard drives that the kernel found when it carried out the device probes will be displayed. shows an example from a system with two IDE disks called ad0 and ad2.
Select Drive for FDisk
Note that ad1 is not listed here. Consider two IDE hard disks where one is the master on the first IDE controller and one is the master on the second IDE controller. If &os; numbered these as ad0 and ad1, everything would work. But if a third disk is later added as the slave device on the first IDE controller, it would now be ad1, and the previous ad1 would become ad2. Because device names are used to find filesystems, some filesystems may no longer appear correctly, requiring a change to the &os; configuration. To work around this, the kernel can be configured to name IDE disks based on where they are and not the order in which they were found. With this scheme, the master disk on the second IDE controller will always be ad2, even if there are no ad0 or ad1 devices. This configuration is the default for the &os; kernel, which is why the display in this example shows ad0 and ad2. The machine on which this screenshot was taken had IDE disks on both master channels of the IDE controllers and no disks on the slave channels. Select the disk on which to install &os;, and then press &gui.ok;. FDisk will start, with a display similar to that shown in . The FDisk display is broken into three sections. The first section, covering the first two lines of the display, shows details about the currently selected disk, including its &os; name, the disk geometry, and the total size of the disk. The second section shows the slices that are currently on the disk, where they start and end, how large they are, the name &os; gives them, and their description and sub-type. This example shows two small unused slices which are artifacts of disk layout schemes on the PC. It also shows one large FAT slice, which appears as C: in &windows;, and an extended slice, which may contain other drive letters in &windows;. The third section shows the commands that are available in FDisk.
Typical Default <application>FDisk</application> Partitions
This step varies, depending on how the disk is to be sliced. To install &os; to the entire disk, which will delete all the other data on this disk, press A, which corresponds to the Use Entire Disk option. The existing slices will be removed and replaced with a small area flagged as unused and one large slice for &os;. Then, select the newly created &os; slice using the arrow keys and press S to mark the slice as being bootable. The screen will then look similar to . Note the A in the Flags column, which indicates that this slice is active, and will be booted from. If an existing slice needs to be deleted to make space for &os;, select the slice using the arrow keys and press D. Then, press C to be prompted for the size of the slice to create. Enter the appropriate value and press Enter. The default value in this box represents the largest possible slice to make, which could be the largest contiguous block of unallocated space or the size of the entire hard disk. If you have already made space for &os; then you can press C to create a new slice. Again, you will be prompted for the size of slice you would like to create.
Fdisk Partition Using Entire Disk
When finished, press Q. Any changes will be saved in &man.sysinstall.8;, but will not yet be written to disk. Install a Boot Manager The next menu provides the option to install a boot manager. In general, install the &os; boot manager if: There is more than one drive and &os; will be installed onto a drive other than the first one. &os; will be installed alongside another operating system on the same disk, and you want to choose whether to start &os; or the other operating system when the computer starts. If &os; is going to be the only operating system on this machine, installed on the first hard disk, then the Standard boot manager will suffice. Choose None if using a third-party boot manager capable of booting &os;. Make a selection and press Enter.
Sysinstall Boot Manager Menu
The help screen, reached by pressing F1, discusses the problems that can be encountered when trying to share the hard disk between operating systems. Creating Slices on Another Drive If there is more than one drive, it will return to the Select Drives screen after the boot manager selection. To install &os; on to more than one disk, select another disk and repeat the slice process using FDisk. If installing &os; on a drive other than the first drive, the &os; boot manager needs to be installed on both drives.
Exit Select Drive
Use Tab to toggle between the last drive selected, &gui.ok;, and &gui.cancel;. Press Tab once to toggle to &gui.ok;, then press Enter to continue with the installation. Creating Partitions Using <application>Disklabel</application> Next, create some partitions inside each slice. Remember that each partition is lettered, from a through to h, and that partitions b, c, and d have conventional meanings that should be adhered to. Certain applications can benefit from particular partition schemes, especially when laying out partitions across more than one disk. However, for a first &os; installation, do not give too much thought to how to partition the disk. It is more important to install &os; and start learning how to use it. You can always re-install &os; to change the partition scheme after becoming more familiar with the operating system. The following scheme features four partitions: one for swap space and three for filesystems. Partition Layout for First Disk Partition Filesystem Size Description a / 1 GB This is the root filesystem. Every other filesystem will be mounted somewhere under this one. 1 GB is a reasonable size for this filesystem as user files should not be stored here and a regular &os; install will put about 128 MB of data here. b N/A 2-3 x RAM The system's swap space is kept on the b partition. Choosing the right amount of swap space can be a bit of an art. A good rule of thumb is that swap space should be two or three times as much as the available physical memory (RAM). There should be at least 64 MB of swap, so if there is less than 32 MB of RAM in the computer, set the swap amount to 64 MB. If there is more than one disk, swap space can be put on each disk. &os; will then use each disk for swap, which effectively speeds up the act of swapping. In this case, calculate the total amount of swap needed and divide this by the number of disks to give the amount of swap to put on each disk. e /var 512 MB to 4096 MB /var contains files that are constantly varying, such as log files and other administrative files. Many of these files are read from or written to extensively during &os;'s day-to-day running. Putting these files on another filesystem allows &os; to optimize the access of these files without affecting other files in other directories that do not have the same access pattern. f /usr Rest of disk (at least 8 GB) All other files will typically be stored in /usr and its subdirectories.
The values above are given as example and should be used by experienced users only. Users are encouraged to use the automatic partition layout called Auto Defaults by the &os; partition editor. If installing &os; on to more than one disk, create partitions in the other configured slices. The easiest way to do this is to create two partitions on each disk, one for the swap space, and one for a filesystem. Partition Layout for Subsequent Disks Partition Filesystem Size Description b N/A See description Swap space can be split across each disk. Even though the a partition is free, convention dictates that swap space stays on the b partition. e /diskn Rest of disk The rest of the disk is taken up with one big partition. This could easily be put on the a partition, instead of the e partition. However, convention says that the a partition on a slice is reserved for the filesystem that will be the root (/) filesystem. Following this convention is not necessary, but &man.sysinstall.8; uses it, so following it makes the installation slightly cleaner. This filesystem can be mounted anywhere; this example mounts it as /diskn, where n is a number that changes for each disk.
Having chosen the partition layout, create it using &man.sysinstall.8;. Message Now, you need to create BSD partitions inside of the fdisk partition(s) just created. If you have a reasonable amount of disk space (1GB or more) and don't have any special requirements, simply use the (A)uto command to allocate space automatically. If you have more specific needs or just don't care for the layout chosen by (A)uto, press F1 for more information on manual layout. [ OK ] [ Press enter or space ] Press Enter to start the &os; partition editor, called Disklabel. shows the display when Disklabel starts. The display is divided into three sections. The first few lines show the name of the disk being worked on and the slice that contains the partitions to create. At this point, Disklabel calls this the Partition name rather than slice name. This display also shows the amount of free space within the slice; that is, space that was set aside in the slice, but that has not yet been assigned to a partition. The middle of the display shows the partitions that have been created, the name of the filesystem that each partition contains, their size, and some options pertaining to the creation of the filesystem. The bottom third of the screen shows the keystrokes that are valid in Disklabel.
Sysinstall Disklabel Editor
Disklabel can automatically create partitions and assign them default sizes. The default sizes are calculated with the help of an internal partition sizing algorithm based on the disk size. Press A to see a display similar to that shown in . Depending on the size of the disk, the defaults may or may not be appropriate. The default partitioning assigns /tmp its own partition instead of being part of the / partition. This helps avoid filling the / partition with temporary files.
Sysinstall Disklabel Editor with Auto Defaults
To replace the default partitions, use the arrow keys to select the first partition and press D to delete it. Repeat this to delete all the suggested partitions. To create the first partition, a, mounted as /, make sure the proper disk slice at the top of the screen is selected and press C. A dialog box will appear, prompting for the size of the new partition, as shown in . The size can be entered as the number of disk blocks to use or as a number followed by either M for megabytes, G for gigabytes, or C for cylinders.
Free Space for Root Partition
The default size shown will create a partition that takes up the rest of the slice. If using the partition sizes described in the earlier example, delete the existing figure using Backspace, and then type in 512M, as shown in . Then press &gui.ok;.
Edit Root Partition Size
After choosing the partition's size, the installer will ask whether this partition will contain a filesystem or swap space. The dialog box is shown in . This first partition will contain a filesystem, so check that FS is selected and press Enter.
Choose the Root Partition Type
Finally, tell Disklabel where the filesystem will be mounted. The dialog box is shown in . Type /, and then press Enter.
Choose the Root Mount Point
The display will then update to show the newly created partition. Repeat this procedure for the other partitions. When creating the swap partition, it will not prompt for the filesystem mount point. When creating the final partition, /usr, leave the suggested size as is to use the rest of the slice. The final &os; DiskLabel Editor screen will appear similar to , although the values chosen may be different. Press Q to finish.
Sysinstall Disklabel Editor
Choosing What to Install Select the Distribution Set Deciding which distribution set to install will depend largely on the intended use of the system and the amount of disk space available. The predefined options range from installing the smallest possible configuration to everything. Those who are new to &unix; or &os; should select one of these canned options. Customizing a distribution set is typically for the more experienced user. Press F1 for more information on the distribution set options and what they contain. When finished reviewing the help, press Enter to return to the Select Distributions Menu. If a graphical user interface is desired, the configuration of &xorg; and selection of a default desktop must be done after the installation of &os;. More information regarding the installation and configuration of a &xorg; can be found in . If compiling a custom kernel is anticipated, select an option which includes the source code. For more information on why a custom kernel should be built or how to build a custom kernel, see . The most versatile system is one that includes everything. If there is adequate disk space, select All, as shown in , by using the arrow keys and pressing Enter. If there is a concern about disk space, consider using an option that is more suitable for the situation. Do not fret over the perfect choice, as other distributions can be added after installation.
Choose Distributions
Installing the Ports Collection After selecting the desired distribution, an opportunity to install the &os; Ports Collection is presented. The Ports Collection is an easy and convenient way to install software as it provides a collection of files that automate the downloading, compiling, and installation of third-party software packages. discusses how to use the Ports Collection. The installation program does not check to see if you have adequate space. Select this option only if you have adequate hard disk space. As of &os; &rel.current;, the &os; Ports Collection takes up about &ports.size; of disk space. You can safely assume a larger value for more recent versions of &os;. User Confirmation Requested Would you like to install the FreeBSD ports collection? This will give you ready access to over &os.numports; ported software packages, at a cost of around &ports.size; of disk space when "clean" and possibly much more than that if a lot of the distribution tarballs are loaded (unless you have the extra CDs from a FreeBSD CD/DVD distribution available and can mount it on /cdrom, in which case this is far less of a problem). The Ports Collection is a very valuable resource and well worth having on your /usr partition, so it is advisable to say Yes to this option. For more information on the Ports Collection & the latest ports, visit: http://www.FreeBSD.org/ports [ Yes ] No Select &gui.yes; with the arrow keys to install the Ports Collection or &gui.no; to skip this option. Press Enter to continue. The Choose Distributions menu will redisplay.
Confirm Distributions
Once satisfied with the options, select Exit with the arrow keys, ensure that &gui.ok; is highlighted, and press Enter to continue. Choosing the Installation Media If installing from a CD/DVD, use the arrow keys to highlight Install from a &os; CD/DVD. Ensure that &gui.ok; is highlighted, then press Enter to proceed with the installation. For other methods of installation, select the appropriate option and follow the instructions. Press F1 to display the Online Help for installation media. Press Enter to return to the media selection menu.
Choose Installation Media
FTP Installation Modes installation network FTP There are three FTP installation modes to choose from: active FTP, passive FTP, or via a HTTP proxy. FTP Active: Install from an FTP server This option makes all FTP transfers use Active mode. This will not work through firewalls, but will often work with older FTP servers that do not support passive mode. If the connection hangs with passive mode (the default), try using active mode. FTP Passive: Install from an FTP server through a firewall This option instructs &man.sysinstall.8; to use passive mode FTP passive mode for all FTP operations. This allows the user to pass through firewalls that do not allow incoming connections on random TCP ports. FTP via a HTTP proxy: Install from an FTP server through a http proxy This option instructs &man.sysinstall.8; to use the HTTP protocol to connect to a proxy for all FTP operations. The proxy will translate the requests and send them to the FTP server. This allows the user to pass through firewalls that do not allow FTP, but offer a HTTP proxy FTP via a HTTP proxy . In this case, specify the proxy in addition to the FTP server. For a proxy FTP server, give the name of the server as part of the username, after an @ sign. The proxy server then fakes the real server. For example, to install from ftp.FreeBSD.org, using the proxy FTP server foo.example.com, listening on port 1234, go to the options menu, set the FTP username to ftp@ftp.FreeBSD.org and the password to an email address. As the installation media, specify FTP (or passive FTP, if the proxy supports it), and the URL ftp://foo.example.com:1234/pub/FreeBSD. Since /pub/FreeBSD from ftp.FreeBSD.org is proxied under foo.example.com, the proxy will fetch the files from ftp.FreeBSD.org as the installer requests them. Committing to the Installation The installation can now proceed if desired. This is also the last chance for aborting the installation to prevent changes to the hard drive. User Confirmation Requested Last Chance! Are you SURE you want to continue the installation? If you're running this on a disk with data you wish to save then WE STRONGLY ENCOURAGE YOU TO MAKE PROPER BACKUPS before proceeding! We can take no responsibility for lost disk contents! [ Yes ] No Select &gui.yes; and press Enter to proceed. The installation time will vary according to the distribution chosen, installation media, and the speed of the computer. There will be a series of messages displayed, indicating the status. The installation is complete when the following message is displayed: Message Congratulations! You now have FreeBSD installed on your system. We will now move on to the final configuration questions. For any option you do not wish to configure, simply select No. If you wish to re-enter this utility after the system is up, you may do so by typing: /usr/sbin/sysinstall. [ OK ] [ Press enter or space ] Press Enter to proceed with post-installation configurations. Selecting &gui.no; and pressing Enter will abort the installation so no changes will be made to the system. The following message will appear: Message Installation complete with some errors. You may wish to scroll through the debugging messages on VTY1 with the scroll-lock feature. You can also choose "No" at the next prompt and go back into the installation menus to retry whichever operations have failed. [ OK ] This message is generated because nothing was installed. Pressing Enter will return to the Main Installation Menu to exit the installation. Post-installation Configuration of various options can be performed after a successful installation. An option can be configured by re-entering the configuration menus before booting the new &os; system or after boot using &man.sysinstall.8; and then selecting the Configure menu. Network Device Configuration If PPP was previously configured for an FTP install, this screen will not display and can be configured after boot as described above. For detailed information on Local Area Networks and configuring &os; as a gateway/router refer to the Advanced Networking chapter. User Confirmation Requested Would you like to configure any Ethernet or PPP network devices? [ Yes ] No To configure a network device, select &gui.yes; and press Enter. Otherwise, select &gui.no; to continue.
Selecting an Ethernet Device
Select the interface to be configured with the arrow keys and press Enter. User Confirmation Requested Do you want to try IPv6 configuration of the interface? Yes [ No ] In this private local area network, the current Internet type protocol (IPv4) was sufficient and &gui.no; was selected with the arrow keys and Enter pressed. If connected to an existing IPv6 network with an RA server, choose &gui.yes; and press Enter. It will take several seconds to scan for RA servers. User Confirmation Requested Do you want to try DHCP configuration of the interface? Yes [ No ] If Dynamic Host Configuration Protocol DHCP) is not required, select &gui.no; with the arrow keys and press Enter. Selecting &gui.yes; will execute &man.dhclient.8; and, if successful, will fill in the network configuration information automatically. Refer to for more information. The following Network Configuration screen shows the configuration of the Ethernet device for a system that will act as the gateway for a Local Area Network.
Set Network Configuration for <replaceable>ed0</replaceable>
Use Tab to select the information fields and fill in appropriate information: Host The fully-qualified hostname, such as k6-2.example.com in this case. Domain The name of the domain that the machine is in, such as example.com for this case. IPv4 Gateway IP address of host forwarding packets to non-local destinations. This must be filled in if the machine is a node on the network. Leave this field blank if the machine is the gateway to the Internet for the network. The IPv4 Gateway is also known as the default gateway or default route. Name server IP address of the local DNS server. There is no local DNS server on this private local area network so the IP address of the provider's DNS server (208.163.10.2) was used. IPv4 address The IP address to be used for this interface was 192.168.0.1 Netmask The address block being used for this local area network is 192.168.0.0 - 192.168.0.255 with a netmask of 255.255.255.0. Extra options to &man.ifconfig.8; Any additional interface-specific options to &man.ifconfig.8;. There were none in this case. Use Tab to select &gui.ok; when finished and press Enter. User Confirmation Requested Would you like to bring the ed0 interface up right now? [ Yes ] No Choosing &gui.yes; and pressing Enter will bring the machine up on the network so it is ready for use. However, this does not accomplish much during installation, since the machine still needs to be rebooted. Configure Gateway User Confirmation Requested Do you want this machine to function as a network gateway? [ Yes ] No If the machine will be acting as the gateway for a local area network and forwarding packets between other machines, select &gui.yes; and press Enter. If the machine is a node on a network, select &gui.no; and press Enter to continue. Configure Internet Services User Confirmation Requested Do you want to configure inetd and the network services that it provides? Yes [ No ] If &gui.no; is selected, various services will not be enabled. These services can be enabled after installation by editing /etc/inetd.conf with a text editor. See for more information. Otherwise, select &gui.yes; to configure these services during install. An additional confirmation will display: User Confirmation Requested The Internet Super Server (inetd) allows a number of simple Internet services to be enabled, including finger, ftp and telnetd. Enabling these services may increase risk of security problems by increasing the exposure of your system. With this in mind, do you wish to enable inetd? [ Yes ] No Select &gui.yes; to continue. User Confirmation Requested inetd(8) relies on its configuration file, /etc/inetd.conf, to determine which of its Internet services will be available. The default FreeBSD inetd.conf(5) leaves all services disabled by default, so they must be specifically enabled in the configuration file before they will function, even once inetd(8) is enabled. Note that services for IPv6 must be separately enabled from IPv4 services. Select [Yes] now to invoke an editor on /etc/inetd.conf, or [No] to use the current settings. [ Yes ] No Selecting &gui.yes; allows services to be enabled by deleting the # at the beginning of the lines representing those services.
Editing <filename>inetd.conf</filename>
Once the edits are complete, press Esc to display a menu which will exit the editor and save the changes. Enabling SSH Login SSH sshd User Confirmation Requested Would you like to enable SSH login? Yes [ No ] Selecting &gui.yes; will enable &man.sshd.8;, the daemon for OpenSSH. This allows secure remote access to the machine. For more information about OpenSSH, see . Anonymous FTP FTP anonymous User Confirmation Requested Do you want to have anonymous FTP access to this machine? Yes [ No ] Deny Anonymous FTP Selecting the default &gui.no; and pressing Enter will still allow users who have accounts with passwords to use FTP to access the machine. Allow Anonymous FTP Anyone can access the machine if anonymous FTP connections are allowed. The security implications should be considered before enabling this option. For more information about security, see . To allow anonymous FTP, use the arrow keys to select &gui.yes; and press Enter. An additional confirmation will display: User Confirmation Requested Anonymous FTP permits un-authenticated users to connect to the system FTP server, if FTP service is enabled. Anonymous users are restricted to a specific subset of the file system, and the default configuration provides a drop-box incoming directory to which uploads are permitted. You must separately enable both inetd(8), and enable ftpd(8) in inetd.conf(5) for FTP services to be available. If you did not do so earlier, you will have the opportunity to enable inetd(8) again later. If you want the server to be read-only you should leave the upload directory option empty and add the -r command-line option to ftpd(8) in inetd.conf(5) Do you wish to continue configuring anonymous FTP? [ Yes ] No This message indicates that the FTP service will also have to be enabled in /etc/inetd.conf to allow anonymous FTP connections. Select &gui.yes; and press Enter to continue. The following screen will display:
Default Anonymous FTP Configuration
Use Tab to select the information fields and fill in appropriate information: UID The user ID to assign to the anonymous FTP user. All files uploaded will be owned by this ID. Group Which group to place the anonymous FTP user into. Comment String describing this user in /etc/passwd. FTP Root Directory Where files available for anonymous FTP will be kept. Upload Subdirectory Where files uploaded by anonymous FTP users will go. The FTP root directory will be put in /var by default. If there is not enough room there for the anticipated FTP needs, use /usr instead by setting the FTP root directory to /usr/ftp. Once satisfied with the values, press Enter to continue. User Confirmation Requested Create a welcome message file for anonymous FTP users? [ Yes ] No If &gui.yes; is selected, press Enter and the &man.ee.1; editor will automatically start.
Edit the FTP Welcome Message
Use the instructions to change the message. Note the file name location at the bottom of the editor screen. Press Esc and a pop-up menu will default to a) leave editor. Press Enter to exit and continue. Press Enter again to save any changes. Configure the Network File System The Network File System (NFS) allows sharing of files across a network. A machine can be configured as a server, a client, or both. Refer to for more information. NFS Server User Confirmation Requested Do you want to configure this machine as an NFS server? Yes [ No ] If there is no need for a NFS server, select &gui.no; and press Enter. If &gui.yes; is chosen, a message will pop-up indicating that /etc/exports must be created. Message Operating as an NFS server means that you must first configure an /etc/exports file to indicate which hosts are allowed certain kinds of access to your local filesystems. Press [Enter] now to invoke an editor on /etc/exports [ OK ] Press Enter to continue. A text editor will start, allowing /etc/exports to be edited.
Editing <filename>exports</filename>
Use the instructions to add the exported filesystems. Note the file name location at the bottom of the editor screen. Press Esc and a pop-up menu will default to a) leave editor. Press Enter to exit and continue. <acronym>NFS</acronym> Client The NFS client allows the machine to access NFS servers. User Confirmation Requested Do you want to configure this machine as an NFS client? Yes [ No ] With the arrow keys, select &gui.yes; or &gui.no; as appropriate and press Enter. System Console Settings There are several options available to customize the system console. User Confirmation Requested Would you like to customize your system console settings? [ Yes ] No To view and configure the options, select &gui.yes; and press Enter.
System Console Configuration Options
A commonly used option is the screen saver. Use the arrow keys to select Saver and then press Enter.
Screen Saver Options
Select the desired screen saver using the arrow keys and then press Enter. The System Console Configuration menu will redisplay. The default time interval is 300 seconds. To change the time interval, select Saver again. At the Screen Saver Options menu, select Timeout using the arrow keys and press Enter. A pop-up menu will appear:
Screen Saver Timeout
The value can be changed, then select &gui.ok; and press Enter to return to the System Console Configuration menu.
System Console Configuration Exit
Select Exit and press Enter to continue with the post-installation configuration. Setting the Time Zone Setting the time zone allows the system to automatically correct for any regional time changes and perform other time zone related functions properly. The example shown is for a machine located in the Eastern time zone of the United States. The selections will vary according to the geographic location. User Confirmation Requested Would you like to set this machine's time zone now? [ Yes ] No Select &gui.yes; and press Enter to set the time zone. User Confirmation Requested Is this machine's CMOS clock set to UTC? If it is set to local time or you don't know, please choose NO here! Yes [ No ] Select &gui.yes; or &gui.no; according to how the machine's clock is configured, then press Enter.
Select the Region
The appropriate region is selected using the arrow keys and then pressing Enter.
Select the Country
Select the appropriate country using the arrow keys and press Enter.
Select the Time Zone
The appropriate time zone is selected using the arrow keys and pressing Enter. Confirmation Does the abbreviation 'EDT' look reasonable? [ Yes ] No Confirm that the abbreviation for the time zone is correct. If it looks okay, press Enter to continue with the post-installation configuration. Mouse Settings This option allows cut and paste in the console and user programs using a 3-button mouse. If using a 2-button mouse, refer to &man.moused.8; for details on emulating the 3-button style. This example depicts a non-USB mouse configuration: User Confirmation Requested Does this system have a PS/2, serial, or bus mouse? [ Yes ] No Select &gui.yes; for a PS/2, serial, or bus mouse, or &gui.no; for a USB mouse, then press Enter.
Select Mouse Protocol Type
Use the arrow keys to select Type and press Enter.
Set Mouse Protocol
The mouse used in this example is a PS/2 type, so the default Auto is appropriate. To change the mouse protocol, use the arrow keys to select another option. Ensure that &gui.ok; is highlighted and press Enter to exit this menu.
Configure Mouse Port
Use the arrow keys to select Port and press Enter.
Setting the Mouse Port
This system had a PS/2 mouse, so the default PS/2 is appropriate. To change the port, use the arrow keys and then press Enter.
Enable the Mouse Daemon
Last, use the arrow keys to select Enable, and press Enter to enable and test the mouse daemon.
Test the Mouse Daemon
Move the mouse around the screen to verify that the cursor responds properly. If it does, select &gui.yes; and press Enter. If not, the mouse has not been configured correctly. Select &gui.no; and try using different configuration options. Select Exit with the arrow keys and press Enter to continue with the post-installation configuration. Install Packages Packages are pre-compiled binaries and are a convenient way to install software. Installation of one package is shown for purposes of illustration. Additional packages can also be added at this time if desired. After installation, &man.sysinstall.8; can be used to add additional packages. User Confirmation Requested The FreeBSD package collection is a collection of hundreds of ready-to-run applications, from text editors to games to WEB servers and more. Would you like to browse the collection now? [ Yes ] No Select &gui.yes; and press Enter to be presented with the Package Selection screens:
Select Package Category
Only packages on the current installation media are available for installation at any given time. All packages available will be displayed if All is selected. Otherwise, select a particular category. Highlight the selection with the arrow keys and press Enter. A menu will display showing all the packages available for the selection made:
Select Packages
The bash shell is shown as selected. Select as many packages as desired by highlighting the package and pressing Space. A short description of each package will appear in the lower left corner of the screen. Press Tab to toggle between the last selected package, &gui.ok;, and &gui.cancel;. Once finished marking the packages for installation, press Tab once to toggle to &gui.ok; and press Enter to return to the Package Selection menu. The left and right arrow keys will also toggle between &gui.ok; and &gui.cancel;. This method can also be used to select &gui.ok; and press Enter to return to the Package Selection menu.
Install Packages
Use the Tab and arrow keys to select [ Install ] and press Enter to see the installation confirmation message:
Confirm Package Installation
Select &gui.ok; and press Enter to start the package installation. Installation messages will appear until all of the installations have completed. Make note if there are any error messages. The final configuration continues after packages are installed. If no packages are selected, select Install to return to the final configuration. Add Users/Groups Add at least one user during the installation so that the system can be used without logging in as root. The root partition is generally small and running applications as root can quickly fill it. A bigger danger is noted below: User Confirmation Requested Would you like to add any initial user accounts to the system? Adding at least one account for yourself at this stage is suggested since working as the "root" user is dangerous (it is easy to do things which adversely affect the entire system). [ Yes ] No Select &gui.yes; and press Enter to continue with adding a user.
Select User
Select User with the arrow keys and press Enter.
Add User Information
The following descriptions will appear in the lower part of the screen as the items are selected with Tab to assist with entering the required information: Login ID The login name of the new user (mandatory). UID The numerical ID for this user (leave blank for automatic choice). Group The login group name for this user (leave blank for automatic choice). Password The password for this user (enter this field with care!). Full name The user's full name (comment). Member groups The groups this user belongs to. Home directory The user's home directory (leave blank for default). Login shell The user's login shell (leave blank for default of /bin/sh). In this example, the login shell was changed from /bin/sh to /usr/local/bin/bash to use the bash shell that was previously installed as a package. Do not use a shell that does not exist or the user will not be able to login. The most common shell used in &os; is the C shell, /bin/tcsh. The user was also added to the wheel group to be able to become a superuser with root privileges. Once satisfied, press &gui.ok; and the User and Group Management menu will redisplay:
Exit User and Group Management
Groups can also be added at this time. Otherwise, this menu may be accessed using &man.sysinstall.8; at a later time. When finished adding users, select Exit with the arrow keys and press Enter to continue the installation. Set the <systemitem class="username">root</systemitem> Password Message Now you must set the system manager's password. This is the password you'll use to log in as "root". [ OK ] [ Press enter or space ] Press Enter to set the root password. The password will need to be typed in twice correctly. Do not forget this password. Notice that the typed password is not echoed, nor are asterisks displayed. New password: Retype new password : The installation will continue after the password is successfully entered. Exiting Install A message will ask if configuration is complete: User Confirmation Requested Visit the general configuration menu for a chance to set any last options? Yes [ No ] Select &gui.no; with the arrow keys and press Enter to return to the Main Installation Menu.
Exit Install
Select [X Exit Install] with the arrow keys and press Enter. The installer will prompt to confirm exiting the installation: User Confirmation Requested Are you sure you wish to exit? The system will reboot. [ Yes ] No Select &gui.yes;. If booting from the CDROM drive, the following message will remind you to remove the disk: Message Be sure to remove the media from the drive. [ OK ] [ Press enter or space ] The CDROM drive is locked until the machine starts to reboot, then the disk can quickly be removed from the drive. Press &gui.ok; to reboot. The system will reboot so watch for any error messages that may appear, see for more details. Configure Additional Network Services TomRhodesContributed by Configuring network services can be a daunting task for users that lack previous knowledge in this area. Since networking and the Internet are critical to all modern operating systems, it is useful to have some understanding of &os;'s extensive networking capabilities. Network services are programs that accept input from anywhere on the network. Since there have been cases where bugs in network services have been exploited by attackers, it is important to only enable needed network services. If in doubt, do not enable a network service until it is needed. Services can be enabled with &man.sysinstall.8; or by editing /etc/rc.conf. Selecting the Networking option will display a menu similar to the one below:
Network Configuration Upper-level
The first option, Interfaces, is covered in . Selecting the AMD option adds support for &man.amd.8;. This is usually used in conjunction with NFS for automatically mounting remote filesystems. Next is the AMD Flags option. When selected, a menu will pop up where specific AMD flags can be entered. The menu already contains a set of default options: -a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map sets the default mount location which is specified here as /.amd_mnt. specifies the default log; however, when &man.syslogd.8; is used, all log activity will be sent to the system log daemon. /host is used to mount an exported file system from a remote host, while /net is used to mount an exported filesystem from an IP address. The default options for AMD exports are defined in /etc/amd.map. FTP anonymous The Anon FTP option permits anonymous FTP connections. Select this option to make this machine an anonymous FTP server. Be aware of the security risks involved with this option. Another menu will be displayed to explain the security risks and configuration in depth. The Gateway menu will configure the machine to be a gateway. This menu can also be used to unset the Gateway option if it was accidentally selected during installation. The Inetd option can be used to configure or completely disable &man.inetd.8;. The Mail option is used to configure the system's default Mail Transfer Agent (MTA). Selecting this option will bring up the following menu:
Select a Default MTA
This menu offers a choice as to which MTA to install and set as the default. An MTA is a mail server which delivers email to users on the system or the Internet. Select Sendmail to install Sendmail as the default MTA. Select Sendmail local to set Sendmail as the default MTA, but disable its ability to receive incoming email from the Internet. The other options, Postfix and Exim, provide alternatives to Sendmail. The next menu after the MTA menu is NFS client. This menu is used to configure the system to communicate with a NFS server which in turn is used to make filesystems available to other machines on the network over the NFS protocol. See for more information about client and server configuration. Below that option is the NFS server option, for setting the system up as an NFS server. This adds the required information to start up the Remote Procedure Call RPC services. RPC is used to coordinate connections between hosts and programs. Next in line is the Ntpdate option, which deals with time synchronization. When selected, a menu like the one below shows up:
Ntpdate Configuration
From this menu, select the server which is geographically closest. This will make the time synchronization more accurate as a farther server may have more connection latency. The next option is the PCNFSD selection. This option will install the net/pcnfsd package from the Ports Collection. This is a useful utility which provides NFS authentication services for systems which are unable to provide their own, such as Microsoft's &ms-dos; operating system. Now, scroll down a bit to see the other options:
Network Configuration Lower-level
RPC communication between NFS servers and clients is managed by &man.rpcbind.8; which is required for NFS servers to operate correctly. Status monitoring is provided by &man.rpc.statd.8; and the reported status is usually held in /var/db/statd.status. The next option is for &man.rpc.lockd.8; which provides file locking services. This is usually used with &man.rpc.statd.8; to monitor which hosts are requesting locks and how frequently they request them. While these last two options are useful for debugging, they are not required for NFS servers and clients to operate correctly. The next menu, Routed, configures the routing daemon. &man.routed.8;, manages network routing tables, discovers multicast routers, and supplies a copy of the routing tables to any physically connected host on the network upon request. This is mainly used for machines which act as a gateway for the local network. If selected, a menu will request the default location of the utility. To accept the default location, press Enter. Yet another menu will ask for the flags to pass to &man.routed.8;. The default of should appear on the screen. The next menu, Rwhod, starts &man.rwhod.8; during system initialization. This utility broadcasts system messages across the network periodically, or collects them when in consumer mode. More information can be found in &man.ruptime.1; and &man.rwho.1;. The next to last option in the list is for &man.sshd.8;, the secure shell server for OpenSSH. It is highly recommended over the standard &man.telnetd.8; and &man.ftpd.8; servers as it is used to create a secure, encrypted connection from one host to another. The final option is TCP Extensions which are defined in RFC 1323 and RFC 1644. While on many hosts this can speed up connections, it can also cause some connections to be dropped. It is not recommended for servers, but may be beneficial for stand alone machines. Once the network services are configured, scroll up to the very top item which is X Exit and continue on to the next configuration item or simply exit &man.sysinstall.8; by selecting X Exit twice then [X Exit Install]. &os; Bootup &os;/&arch.i386; Bootup If everything went well, messages will scroll along the screen and a login prompt will appear. To view these messages, press Scroll-Lock then use PgUp and PgDn. Press Scroll-Lock again to return to the prompt. All of the messages may not display due to buffer limitations, but they can be read after logging using &man.dmesg.8;. Login using the username and password which were set during installation. Avoid logging in as root except when necessary. Typical boot messages (version information omitted): Copyright (c) 1992-2002 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. Timecounter "i8254" frequency 1193182 Hz CPU: AMD-K6(tm) 3D processor (300.68-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x580 Stepping = 0 Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX> AMD Features=0x80000800<SYSCALL,3DNow!> real memory = 268435456 (262144K bytes) config> di sn0 config> di lnc0 config> di le0 config> di ie0 config> di fe0 config> di cs0 config> di bt0 config> di aic0 config> di aha0 config> di adv0 config> q avail memory = 256311296 (250304K bytes) Preloaded elf kernel "kernel" at 0xc0491000. Preloaded userconfig_script "/boot/kernel.conf" at 0xc049109c. md0: Malloc disk Using $PIR table, 4 entries at 0xc00fde60 npx0: <math processor> on motherboard npx0: INT 16 interface pcib0: <Host to PCI bridge> on motherboard pci0: <PCI bus> on pcib0 pcib1: <VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 on pci0 pci1: <PCI bus> on pcib1 pci1: <Matrox MGA G200 AGP graphics accelerator> at 0.0 irq 11 isab0: <VIA 82C586 PCI-ISA bridge> at device 7.0 on pci0 isa0: <ISA bus> on isab0 atapci0: <VIA 82C586 ATA33 controller> port 0xe000-0xe00f at device 7.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 uhci0: <VIA 83C572 USB controller> port 0xe400-0xe41f irq 10 at device 7.2 on pci0 usb0: <VIA 83C572 USB controller> on uhci0 usb0: USB revision 1.0 uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered chip1: <VIA 82C586B ACPI interface> at device 7.3 on pci0 ed0: <NE2000 PCI Ethernet (RealTek 8029)> port 0xe800-0xe81f irq 9 at device 10.0 on pci0 ed0: address 52:54:05:de:73:1b, type NE2000 (16 bit) isa0: too many dependant configs (8) isa0: unexpected small tag 14 fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: <1440-KB 3.5" drive> on fdc0 drive 0 atkbdc0: <keyboard controller (i8042)> at port 0x60-0x64 on isa0 atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0 kbd0 at atkbd0 psm0: <PS/2 Mouse> irq 12 on atkbdc0 psm0: model Generic PS/2 mouse, device ID 0 vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0 sc0: <System console> at flags 0x1 on isa0 sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/15 bytes threshold ppbus0: IEEE1284 device found /NIBBLE Probing for PnP devices on ppbus0: plip0: <PLIP network interface> on ppbus0 lpt0: <Printer> on ppbus0 lpt0: Interrupt-driven port ppi0: <Parallel I/O> on ppbus0 ad0: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata0-master using UDMA33 ad2: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata1-master using UDMA33 acd0: CDROM <DELTA OTC-H101/ST3 F/W by OIPD> at ata0-slave using PIO4 Mounting root from ufs:/dev/ad0s1a swapon: adding /dev/ad0s1b as swap device Automatic boot in progress... /dev/ad0s1a: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1a: clean, 48752 free (552 frags, 6025 blocks, 0.9% fragmentation) /dev/ad0s1f: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1f: clean, 128997 free (21 frags, 16122 blocks, 0.0% fragmentation) /dev/ad0s1g: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1g: clean, 3036299 free (43175 frags, 374073 blocks, 1.3% fragmentation) /dev/ad0s1e: filesystem CLEAN; SKIPPING CHECKS /dev/ad0s1e: clean, 128193 free (17 frags, 16022 blocks, 0.0% fragmentation) Doing initial network setup: hostname. ed0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 inet6 fe80::5054::5ff::fede:731b%ed0 prefixlen 64 tentative scopeid 0x1 ether 52:54:05:de:73:1b lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x8 inet6 ::1 prefixlen 128 inet 127.0.0.1 netmask 0xff000000 Additional routing options: IP gateway=YES TCP keepalive=YES routing daemons:. additional daemons: syslogd. Doing additional network setup:. Starting final network daemons: creating ssh RSA host key Generating public/private rsa1 key pair. Your identification has been saved in /etc/ssh/ssh_host_key. Your public key has been saved in /etc/ssh/ssh_host_key.pub. The key fingerprint is: cd:76:89:16:69:0e:d0:6e:f8:66:d0:07:26:3c:7e:2d root@k6-2.example.com creating ssh DSA host key Generating public/private dsa key pair. Your identification has been saved in /etc/ssh/ssh_host_dsa_key. Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub. The key fingerprint is: f9:a1:a9:47:c4:ad:f9:8d:52:b8:b8:ff:8c:ad:2d:e6 root@k6-2.example.com. setting ELF ldconfig path: /usr/lib /usr/lib/compat /usr/X11R6/lib /usr/local/lib a.out ldconfig path: /usr/lib/aout /usr/lib/compat/aout /usr/X11R6/lib/aout starting standard daemons: inetd cron sshd usbd sendmail. Initial rc.i386 initialization:. rc.i386 configuring syscons: blank_time screensaver moused. Additional ABI support: linux. Local package initialization:. Additional TCP options:. FreeBSD/i386 (k6-2.example.com) (ttyv0) login: rpratt Password: Generating the RSA and DSA keys may take some time on slower machines. This happens only on the initial boot-up of a new installation. Subsequent boots will be faster. If &xorg; has been configured and a default desktop chosen, it can be started by typing startx at the command line. &os; Shutdown It is important to properly shutdown the operating system. Do not just turn off the power. First, become the superuser using &man.su.1; and entering the root password. This will work only if the user is a member of wheel. Otherwise, login as root. To shutdown the system, type shutdown -h now. The operating system has halted. Please press any key to reboot. It is safe to turn off the power after the shutdown command has been issued and the message Please press any key to reboot appears. If any key is pressed instead of turning off the power switch, the system will reboot. The Ctrl Alt Del key combination can also be used to reboot the system; however, this is not recommended. Troubleshooting installation troubleshooting This section covers basic installation troubleshooting of common problems. There are also a few questions and answers for people wishing to dual-boot &os; with &windows;. If Something Goes Wrong Due to various limitations of the PC architecture, it is impossible for device probing to be 100% reliable. However, there are a few things to try if it fails. Check the Hardware Notes document for the version of &os; to make sure the hardware is supported. If the hardware is supported but still experiences lock-ups or other problems, build a custom kernel to add in support for devices which are not present in the GENERIC kernel. The default kernel assumes that most hardware devices are in their factory default configuration in terms of IRQs, I/O addresses, and DMA channels. If the hardware has been reconfigured, create a custom kernel configuration file and recompile to tell &os; where to find things. It is also possible that a probe for a device not present will cause a later probe for another device that is present to fail. In that case, the probes for the conflicting driver(s) should be disabled. Some installation problems can be avoided or alleviated by updating the firmware on various hardware components, most notably the motherboard BIOS. Most motherboard and computer manufacturers have a website where upgrade information may be located. Most manufacturers strongly advise against upgrading the motherboard BIOS unless there is a good reason for doing so, such as a critical update. The upgrade process can go wrong, causing permanent damage to the BIOS chip. Using &windows; Filesystems At this time, &os; does not support file systems compressed with the Double Space™ application. Therefore the file system will need to be uncompressed before &os; can access the data. This can be done by running the Compression Agent located in the Start> Programs > System Tools menu. &os; can support &ms-dos; file systems (sometimes called FAT file systems). The &man.mount.msdosfs.8; command grafts such file systems onto the existing directory hierarchy, allowing the file system's contents to be accessed. The &man.mount.msdosfs.8; program is not usually invoked directly; instead, it is called by the system through a line in /etc/fstab or by using &man.mount.8; with the appropriate parameters. A typical line in /etc/fstab is: /dev/ad0sN /dos msdosfs rw 0 0 /dos must already exist for this to work. For details about the format of /etc/fstab, see &man.fstab.5;. A typical call to &man.mount.8; for a FAT filesystem looks like: &prompt.root; mount -t msdosfs /dev/ad0s1 /mnt In this example, the FAT filesystem is located on the first partition of the primary hard disk. The output from &man.dmesg.8; and &man.mount.8; should produce enough information to give an idea of the partition layout. &os; may number FAT partitions differently than other operating systems. In particular, extended partitions are usually given higher slice numbers than primary partitions. Use &man.fdisk.8; to help determine which slices belong to &os; and which belong to other operating systems. Troubleshooting Questions and Answers My system hangs while probing hardware during boot or it behaves strangely during install. &os; makes extensive use of the system ACPI service on the i386, amd64, and ia64 platforms to aid in system configuration if it is detected during boot. Unfortunately, some bugs still exist in the ACPI driver and various system motherboards. The use of ACPI can be disabled by setting hint.acpi.0.disabled in the third stage boot loader: set hint.acpi.0.disabled="1" This is reset each time the system is booted, so it is necessary to add hint.acpi.0.disabled="1" to /boot/loader.conf to make this change permanent. More information about the boot loader can be found in . When booting from the hard disk for the first time after installing &os;, the kernel loads and probes hardware, but stops with messages like: changing root device to ad1s1a panic: cannot mount root What is wrong? This can occur when the boot disk is not the first disk in the system. The BIOS uses a different numbering scheme to &os;, and working out which numbers correspond to which is difficult to get right. If this occurs, tell &os; where the root filesystem is by specifying the BIOS disk number, the disk type, and the &os; disk number for that type. Consider two IDE disks, each configured as the master on their respective IDE bus, where &os; should be booted from the second disk. The BIOS sees these as disk 0 and disk 1, while &os; sees them as ad0 and ad2. If &os; is on BIOS disk 1, of type ad and the &os; disk number is 2, this is the correct value: 1:ad(2,a)kernel Note that if there is a slave on the primary bus, the above is not necessary and is effectively wrong. The second situation involves booting from a SCSI disk when there are one or more IDE disks in the system. In this case, the &os; disk number is lower than the BIOS disk number. For two IDE disks and a SCSI disk, where the SCSI disk is BIOS disk 2, type da, and &os; disk number 0, the correct value is: 2:da(0,a)kernel This tells &os; to boot from BIOS disk 2, which is the first SCSI disk in the system. If there is only IDE disk, use 1: instead. Once the correct value to use is determined, put the command in /boot.config using a text editor. Unless instructed otherwise, &os; will use the contents of this file as the default response to the boot: prompt. When booting from the hard disk for the first time after installing &os;, the Boot Manager prompt just prints F? at the boot menu and the boot will not go any further. The hard disk geometry was set incorrectly in the partition editor when &os; was installed. Go back into the partition editor and specify the actual geometry of the hard disk. &os; must be reinstalled again from the beginning with the correct geometry. For a dedicated &os; system that does not need future compatibility with another operating system, use the entire disk by selecting A in the installer's partition editor. The system finds the &man.ed.4; network card but continuously displays device timeout errors. The card is probably on a different IRQ from what is specified in /boot/device.hints. The &man.ed.4; driver does not use software configuration by default, but it will if -1 is specified in the hints for the interface. Either move the jumper on the card to the configuration setting or specify the IRQ as -1 by setting the hint hint.ed.0.irq="-1". This tells the kernel to use the software configuration. Another possibility is that the card is at IRQ 9, which is shared by IRQ 2 and frequently a cause of problems, especially if a VGA card is using IRQ 2. Do not use IRQ 2 or 9 if at all possible. When &man.sysinstall.8; is usedin an &xorg; terminal, the yellow font is difficult to read against the light gray background. Is there a way to provide higher contrastcolor contrast for this application? If the default colors chosen by &man.sysinstall.8; make text illegible while using x11/xterm or x11/rxvt, add the following to ~/.Xdefaults to get a darker background gray: XTerm*color7: #c0c0c0 Advanced Installation Guide ValentinoVaschettoContributed by MarcFonvieilleUpdated by This section describes how to install &os; in exceptional cases. Installing &os; on a System Without a Monitor or Keyboard installation headless (serial console) serial console This type of installation is called a headless install because the machine to be installed does not have either an attached monitor or a VGA output. This type of installation is possible using a serial console, another machine which acts as the main display and keyboard. To do this, follow the steps to create an installation USB stick, explained in , or download the correct installation ISO image as described in . To modify the installation media to boot into a serial console, follow these steps. If using a CD/DVD media, skip the first step): Enabling the Installation USB Stick to Boot into a Serial Console &man.mount.8; By default, booting into the USB stick boots into the installer. To instead boot into a serial console, mount the USB disk onto a &os; system using &man.mount.8;: &prompt.root; mount /dev/da0a /mnt Adapt the device node and the mount point to the situation. Once the USB stick is mounted, set it to boot into a serial console. Add this line to /boot/loader.conf on the USB stick: &prompt.root; echo 'console="comconsole"' >> /mnt/boot/loader.conf Now that the USB is stick configured correctly, unmount the disk using &man.umount.8;: &prompt.root; umount /mnt Now, unplug the USB stick and jump directly to the third step of this procedure. Enabling the Installation CD/DVD to Boot into a Serial Console &man.mount.8; By default, when booting into the installation CD/DVD, &os; boots into its normal install mode. To instead boot into a serial console, extract, modify, and regenerate the ISO image before burning it to the CD/DVD media. From the &os; system with the saved installation ISO image, use &man.tar.1; to extract all the files: &prompt.root; mkdir /path/to/headless-iso &prompt.root; tar -C /path/to/headless-iso -pxvf &os;-&rel.current;-RELEASE-i386-disc1.iso Next, set the installation media to boot into a serial console. Add this line to the /boot/loader.conf of the extracted ISO image: &prompt.root; echo 'console="comconsole"' >> /path/to/headless-iso/boot/loader.conf Then, create a new ISO image from the modified tree. This example uses &man.mkisofs.8; from the sysutils/cdrtools package or port: &prompt.root; mkisofs -v -b boot/cdboot -no-emul-boot -r -J -V "Headless_install" \ -o Headless-&os;-&rel2.current;-RELEASE-i386-disc1.iso/path/to/headless-iso Now that the ISO image is configured correctly, burn it to a CD/DVD media using a burning application. Connecting the Null-modem Cable null-modem cable Connect a null-modem cable to the serial ports of the two machines. A normal serial cable will not work. A null-modem cable is required. Booting Up for the Install It is now time to go ahead and start the install. Plug in the USB stick or insert the CD/DVD media in the headless install machine and power it on. Connecting to the Headless Machine &man.cu.1; Next, connect to that machine with &man.cu.1;: &prompt.root; cu -l /dev/cuau0 The headless machine can now be controlled using &man.cu.1;. It will load the kernel and then display a selection of which type of terminal to use. Select the &os; color console and proceed with the installation. Preparing Custom Installation Media Some situations may require a customized &os; installation media and/or source. This might be physical media or a source that &man.sysinstall.8; can use to retrieve the installation files. Some example situations include: A local network with many machines has a private FTP server hosting the &os; installation files which the machines should use for installation. &os; does not recognize the CD/DVD drive but &windows; does. In this case, copy the &os; installation files to a &windows; partition on the same computer, and then install &os; using those files. The computer to install does not have a CD/DVD drive or a network card, but can be connected using a null-printer cable to a computer that does. A tape will be used to install &os;. Creating an Installation ISO As part of each release, the &os; Project provides ISO images for each supported architecture. These images can be written (burned) to CD or DVD media using a burning application, and then used to install &os;. If a CD/DVD writer is available, this is the easiest way to install &os;. Download the Correct ISO Images The ISO images for each release can be downloaded from ftp://ftp.FreeBSD.org/pub/FreeBSD/ISO-IMAGES-arch/version or the closest mirror. Substitute arch and version as appropriate. An image directory normally contains the following images: &os; ISO Image Names and Meanings Filename Contents &os;-version-RELEASE-arch-bootonly.iso This CD image starts the installation process by booting from a CD-ROM drive but it does not contain the support for installing &os; from the CD itself. Perform a network based install, such as from an FTP server, after booting from this CD. &os;-version-RELEASE-arch-dvd1.iso.gz This DVD image contains everything necessary to install the base &os; operating system, a collection of pre-built packages, and the documentation. It also supports booting into a livefs based rescue mode. &os;-version-RELEASE-arch-memstick.img This image can be written to a USB memory stick in order to install machines capable of booting from USB drives. It also supports booting into a livefs based rescue mode. The only included package is the documentation package. &os;-version-RELEASE-arch-disc1.iso This image can be written to a USB memory stick in order to install machines capable of booting from USB drives. Similar to the bootonly.iso image, it does not contain the distribution sets on the medium itself, but does support network-based installations (for example, via ftp). &os;-version-RELEASE-arch-disc1.iso This CD image contains the base &os; operating system and the documentation package but no other packages. &os;-version-RELEASE-arch-disc2.iso A CD image with as many third-party packages as would fit on the disc. This image is not available for &os; 9.X. &os;-version-RELEASE-arch-disc3.iso Another CD image with as many third-party packages as would fit on the disc. This image is not available for &os; 9.X. &os;-version-RELEASE-arch-livefs.iso This CD image contains support for booting into a livefs based rescue mode but does not support doing an install from the CD itself.
When performing a CD installation, download either the bootonly ISO image or disc1. Do not download both, since disc1 contains everything that the bootonly ISO image contains. Use the bootonly ISO to perform a network install over the Internet. Additional software can be installed as needed using the Ports Collection as described in . Use dvd1 to install &os; and a selection of third-party packages from the disc. Burn the Media Next, write the downloaded image(s) to disc. If using another &os; system, refer to for instructions. If using another platform, use any burning utility that exists for that platform. The images are in the standard ISO format which most CD writing applications support. To build a customized release of &os;, refer to the Release Engineering Article. Creating a Local FTP Site with a &os; Disc installation network FTP &os; discs are laid out in the same way as the FTP site. This makes it easy to create a local FTP site that can be used by other machines on a network to install &os;. On the &os; computer that will host the FTP site, ensure that the CD/DVD is in the drive and mounted: &prompt.root; mount /cdrom Create an account for anonymous FTP. Use &man.vipw.8; to insert this line: ftp:*:99:99::0:0:FTP:/cdrom:/nonexistent Ensure that the FTP service is enabled in /etc/inetd.conf. Anyone with network connectivity to the machine can now chose a media type of FTP and type in ftp://your machine after picking Other in the FTP sites menu during the install. If the boot media for the FTP clients is not precisely the same version as that provided by the local FTP site, &man.sysinstall.8; will not complete the installation. To override this, go into the Options menu and change the distribution name to any. This approach is acceptable for a machine on the local network which is protected by a firewall. Offering anonymous FTP services to other machines over the Internet exposes the computer to increased security risks. It is strongly recommended to follow good security practices when providing services over the Internet. Installing from an &windows; Partition installation from &windows; To prepare for an installation from a &windows; partition, copy the files from the distribution into a directory in the root directory of the partition, such as c:\freebsd. Since the directory structure must be reproduced, it is recommended to use robocopy when copying from a CD/DVD. For example, to prepare for a minimal installation of &os;: C:\> md c:\freebsd C:\> robocopy e:\bin c:\freebsd\bin\ /s C:\> robocopy e:\manpages c:\freebsd\manpages\ /s This example assumes that C: has enough free space and E: is where the CD/DVD is mounted. Alternatively, download the distribution from ftp.FreeBSD.org. Each distribution is in its own directory; for example, the base distribution can be found in the &rel2.current;/base/ directory. Copy the distributions to install from a &windows; partition to c:\freebsd. Both the base and kernel distributions are needed for the most minimal installation. Before Installing over a Network installation network serial (PPP) installation network parallel (PLIP) installation network Ethernet There are three types of network installations available: Ethernet, PPP, and PLIP. For the fastest possible network installation, use an Ethernet adapter. &os; supports most common Ethernet cards. A list of supported cards is provided in the Hardware Notes for each release of &os;. If using a supported PCMCIA Ethernet card, be sure that it is plugged in before the system is powered on as &os; does not support hot insertion of PCMCIA cards during installation. Make note of the system's IP address, subnet mask, hostname, default gateway address, and DNS server addresses if these values are statically assigned. If installing by FTP through a HTTP proxy, make note of the proxy's address. If you do not know these values, ask the system administrator or ISP before trying this type of installation. If using a dialup modem, have the service provider's PPP information handy as it is needed early in the installation process. If PAP or CHAP are used to connect to the ISP without using a script, type dial at the &os; ppp prompt. Otherwise, know how to dial the ISP using the AT commands specific to the modem, as the PPP dialer provides only a simple terminal emulator. Refer to and &url.books.faq;/ppp.html for further information. Logging can be directed to the screen using set log local .... If a hard-wired connection to another &os; machine is available, the installation can occur over a null-modem parallel port cable. The data rate over the parallel port is higher than what is typically possible over a serial line. Before Installing via <acronym>NFS</acronym> installation network NFS To perform an NFS installation, copy the needed &os; distribution files to an NFS server and then point the installer's NFS media selection to it. If the server supports only a privileged port, set the option NFS Secure in the Options menu so that the installation can proceed. If using a poor quality Ethernet card which suffers from slow transfer rates, toggle the NFS Slow flag to on. In order for an NFS installation to work, the server must support subdir mounts. For example, if the &os; &rel.current; distribution lives on: ziggy:/usr/archive/stuff/FreeBSD, ziggy will have to allow the direct mounting of /usr/archive/stuff/FreeBSD, not just /usr or /usr/archive/stuff. In &os;, this is controlled by using in /etc/exports. Other NFS servers may have different conventions. If the server is displaying permission denied messages, it is likely that this is not enabled properly. Index: head/en_US.ISO8859-1/books/handbook/jails/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/jails/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/jails/chapter.xml (revision 46052) @@ -1,1624 +1,1625 @@ + xml:id="jails"> + Jails MatteoRiondatoContributed by jails Synopsis Since system administration is a difficult task, many tools have been developed to make life easier for the administrator. These tools often enhance the way systems are installed, configured, and maintained. One of the tools which can be used to enhance the security of a &os; system is jails. Jails have been available since &os; 4.X and continue to be enhanced in their usefulness, performance, reliability, and security. Jails build upon the &man.chroot.2; concept, which is used to change the root directory of a set of processes, creating a safe environment, separate from the rest of the system. Processes created in the chrooted environment can not access files or resources outside of it. For that reason, compromising a service running in a chrooted environment should not allow the attacker to compromise the entire system. However, a chroot has several limitations. It is suited to easy tasks which do not require much flexibility or complex, advanced features. Over time many ways have been found to escape from a chrooted environment, making it a less than ideal solution for securing services. Jails improve on the concept of the traditional chroot environment in several ways. In a traditional chroot environment, processes are only limited in the part of the file system they can access. The rest of the system resources, system users, running processes, and the networking subsystem are shared by the chrooted processes and the processes of the host system. Jails expand this model by virtualizing access to the file system, the set of users, and the networking subsystem. More fine-grained controls are available for tuning the access of a jailed environment. Jails can be considered as a type of operating system-level virtualization. A jail is characterized by four elements: A directory subtree: the starting point from which a jail is entered. Once inside the jail, a process is not permitted to escape outside of this subtree. A hostname: which will be used by the jail. An IP address: which is assigned to the jail. The IP address of a jail is often an alias address for an existing network interface. A command: the path name of an executable to run inside the jail. The path is relative to the root directory of the jail environment. Jails have their own set of users and their own root account which are limited to the jail environment. The root account of a jail is not allowed to perform operations to the system outside of the associated jail environment. This chapter provides an overview of jail terminology are how to use &os; jails. Jails are a powerful tool for system administrators, but their basic usage can also be useful for advanced users. After reading this chapter, you will know: What a jail is and what purpose it may serve in &os; installations. How to build, start, and stop a jail. The basics of jail administration, both from inside and outside the jail. Jails are a powerful tool, but they are not a security panacea. While it is not possible for a jailed process to break out on its own, there are several ways in which an unprivileged user outside the jail can cooperate with a privileged user inside the jail to obtain elevated privileges in the host environment. Most of these attacks can be mitigated by ensuring that the jail root is not accessible to unprivileged users in the host environment. As a general rule, untrusted users with privileged access to a jail should not be given access to the host environment. Terms Related to Jails To facilitate better understanding of parts of the &os; system related to jails, their internals and the way they interact with the rest of &os;, the following terms are used further in this chapter: &man.chroot.8; (command) Utility, which uses &man.chroot.2; &os; system call to change the root directory of a process and all its descendants. &man.chroot.2; (environment) The environment of processes running in a chroot. This includes resources such as the part of the file system which is visible, user and group IDs which are available, network interfaces and other IPC mechanisms, etc. &man.jail.8; (command) The system administration utility which allows launching of processes within a jail environment. host (system, process, user, etc.) The controlling system of a jail environment. The host system has access to all the hardware resources available, and can control processes both outside of and inside a jail environment. One of the important differences of the host system from a jail is that the limitations which apply to superuser processes inside a jail are not enforced for processes of the host system. hosted (system, process, user, etc.) A process, user or other entity, whose access to resources is restricted by a &os; jail. Creating and Controlling Jails Some administrators divide jails into the following two types: complete jails, which resemble a real &os; system, and service jails, dedicated to one application or service, possibly running with privileges. This is only a conceptual division and the process of building a jail is not affected by it. When creating a complete jail there are two options for the source of the userland: use prebuilt binaries (such as those supplied on an install media) or build from source. To install the userland from installation media, first create the root directory for the jail. This can be done by setting the DESTDIR variable to the proper location. The command to use depends on which shell is being used. When using &man.sh.1;: &prompt.root; export DESTDIR=/here/is/the/jail If csh/tcsh is used, execute this instead: &prompt.root; setenv DESTDIR /here/is/the/jail Mount the install media as covered in &man.mdconfig.8; when using the install ISO: &prompt.root; mount -t cd9660 /dev/`mdconfig -f cdimage.iso` /mnt Extract the binaries from the tarballs on the install media into the declared destination. Minimally, only the base set needs to be extracted, but a complete install can be performed when preferred. To install just the base system, run the next command when using &os; 9.x or newer: &prompt.root; tar -xf /mnt/freebsd_install/usr/freebsd_dist/base.txz -C $DESTDIR On &os; 8.x systems, use this command instead: &prompt.root; /mnt/8.4-RELEASE/base/install.sh To install everything but the kernel, issue this command: When using &man.sh.1; on &os; 9.x and newer, issue this command: &prompt.root; for sets in BASE DOC GAMES PORTS; do (tar -xf /mnt/FREEBSD_INSTALL/USR/FREEBSD_DIST/$sets.TXZ -C $DESTDIR) ; done When using &os; 8.x, run this: &prompt.root; cd /mnt/8.4-RELEASE; for dir in base catpages dict doc games info manpages ports; do (cd $dir; ./install.sh) ; done If csh/tcsh is used on &os; 9.x and newer, execute this command: &prompt.root; foreach sets ( BASE DOC GAMES PORTS ) tar -xf /mnt/FREEBSD_INSTALL/USR/FREEBSD_DIST/$sets.TXZ -C $DESTDIR done On &os; 8.x, run this command: &prompt.root; foreach dir ( base catpages dict doc games info manpages ports ) cd /mnt/8.4-RELEASE/$dir; ./install.sh done The &man.jail.8; manual page explains the procedure for building a jail: &prompt.root; setenv D /here/is/the/jail &prompt.root; mkdir -p $D &prompt.root; cd /usr/src &prompt.root; make buildworld &prompt.root; make installworld DESTDIR=$D &prompt.root; make distribution DESTDIR=$D &prompt.root; mount -t devfs devfs $D/dev Selecting a location for a jail is the best starting point. This is where the jail will physically reside within the file system of the jail's host. A good choice can be /usr/jail/jailname, where jailname is the hostname identifying the jail. The /usr/ file system usually has enough space for the jail file system, which for complete jails is, essentially, a replication of every file present in a default installation of the &os; base system. If you have already rebuilt your userland using make world or make buildworld, you can skip this step and install your existing userland into the new jail. This command will populate the directory subtree chosen as jail's physical location on the file system with the necessary binaries, libraries, manual pages and so on. The distribution target for make installs every needed configuration file. In simple words, it installs every installable file of /usr/src/etc/ to the /etc directory of the jail environment: $D/etc/. Mounting the &man.devfs.8; file system inside a jail is not required. On the other hand, any, or almost any application requires access to at least one device, depending on the purpose of the given application. It is very important to control access to devices from inside a jail, as improper settings could permit an attacker to do nasty things in the jail. Control over &man.devfs.8; is managed through rulesets which are described in the &man.devfs.8; and &man.devfs.conf.5; manual pages. Once a jail is installed, it can be started by using the &man.jail.8; utility. The &man.jail.8; utility takes four mandatory arguments which are described in the . Other arguments may be specified too, e.g., to run the jailed process with the credentials of a specific user. The argument depends on the type of the jail; for a virtual system, /etc/rc is a good choice, since it will replicate the startup sequence of a real &os; system. For a service jail, it depends on the service or application that will run within the jail. Jails are often started at boot time and the &os; rc mechanism provides an easy way to do this. A list of the jails which are enabled to start at boot time should be added to the &man.rc.conf.5; file: jail_enable="YES" # Set to NO to disable starting of any jails jail_list="www" # Space separated list of names of jails Jail names in jail_list should contain alphanumeric characters only. For each jail listed in jail_list, a group of &man.rc.conf.5; settings, which describe the particular jail, should be added: jail_www_rootdir="/usr/jail/www" # jail's root directory jail_www_hostname="www.example.org" # jail's hostname jail_www_ip="192.168.0.10" # jail's IP address jail_www_devfs_enable="YES" # mount devfs in the jail The default startup of jails configured in &man.rc.conf.5;, will run the /etc/rc script of the jail, which assumes the jail is a complete virtual system. For service jails, the default startup command of the jail should be changed, by setting the jail_jailname_exec_start option appropriately. For a full list of available options, please see the &man.rc.conf.5; manual page. &man.service.8; can be used to start or stop a jail by hand, if an entry for it exists in rc.conf: &prompt.root; service jail start www &prompt.root; service jail stop www A clean way to shut down a &man.jail.8; is not available at the moment. This is because commands normally used to accomplish a clean system shutdown cannot be used inside a jail. The best way to shut down a jail is to run the following command from within the jail itself or using the &man.jexec.8; utility from outside the jail: &prompt.root; sh /etc/rc.shutdown More information about this can be found in the &man.jail.8; manual page. Fine Tuning and Administration There are several options which can be set for any jail, and various ways of combining a host &os; system with jails, to produce higher level applications. This section presents: Some of the options available for tuning the behavior and security restrictions implemented by a jail installation. Some of the high-level applications for jail management, which are available through the &os; Ports Collection, and can be used to implement overall jail-based solutions. System Tools for Jail Tuning in &os; Fine tuning of a jail's configuration is mostly done by setting &man.sysctl.8; variables. A special subtree of sysctl exists as a basis for organizing all the relevant options: the security.jail.* hierarchy of &os; kernel options. Here is a list of the main jail-related sysctls, complete with their default value. Names should be self-explanatory, but for more information about them, please refer to the &man.jail.8; and &man.sysctl.8; manual pages. security.jail.set_hostname_allowed: 1 security.jail.socket_unixiproute_only: 1 security.jail.sysvipc_allowed: 0 security.jail.enforce_statfs: 2 security.jail.allow_raw_sockets: 0 security.jail.chflags_allowed: 0 security.jail.jailed: 0 These variables can be used by the system administrator of the host system to add or remove some of the limitations imposed by default on the root user. Note that there are some limitations which cannot be removed. The root user is not allowed to mount or unmount file systems from within a &man.jail.8;. The root inside a jail may not load or unload &man.devfs.8; rulesets, set firewall rules, or do many other administrative tasks which require modifications of in-kernel data, such as setting the securelevel of the kernel. The base system of &os; contains a basic set of tools for viewing information about the active jails, and attaching to a jail to run administrative commands. The &man.jls.8; and &man.jexec.8; commands are part of the base &os; system, and can be used to perform the following simple tasks: Print a list of active jails and their corresponding jail identifier (JID), IP address, hostname and path. Attach to a running jail, from its host system, and run a command inside the jail or perform administrative tasks inside the jail itself. This is especially useful when the root user wants to cleanly shut down a jail. The &man.jexec.8; utility can also be used to start a shell in a jail to do administration in it; for example: &prompt.root; jexec 1 tcsh High-Level Administrative Tools in the &os; Ports Collection Among the many third-party utilities for jail administration, one of the most complete and useful is sysutils/ezjail. It is a set of scripts that contribute to &man.jail.8; management. Please refer to the handbook section on ezjail for more information. Keeping Jails Patched and up to Date Jails should be kept up to date from the host operating system as attempting to patch userland from within the jail may likely fail as the default behaviour in FreeBSD is to disallow the use of &man.chflags.1; in a jail which prevents the replacement of some files. It is possible to change this behavior but it is recommended to use &man.freebsd-update.8; to maintain jails instead. Use to specify the path of the jail to be updated. &prompt.root; freebsd-update -b /here/is/the/jail fetch &prompt.root; freebsd-update -b /here/is/the/jail install Updating Multiple Jails Daniel Gerzo Contributed by Simon L. B. Nielsen Based upon an idea presented by Ken Tom And an article written by The management of multiple jails can become problematic because every jail has to be rebuilt from scratch whenever it is upgraded. This can be time consuming and tedious if a lot of jails are created and manually updated. This section demonstrates one method to resolve this issue by safely sharing as much as is possible between jails using read-only &man.mount.nullfs.8; mounts, so that updating is simpler. This makes it more attractive to put single services, such as HTTP, DNS, and SMTP, into individual jails. Additionally, it provides a simple way to add, remove, and upgrade jails. Simpler solutions exist, such as ezjail, which provides an easier method of administering &os; jails but is less versatile than this setup. ezjail is covered in more detail in . The goals of the setup described in this section are: Create a simple and easy to understand jail structure that does not require running a full installworld on each and every jail. Make it easy to add new jails or remove existing ones. Make it easy to update or upgrade existing jails. Make it possible to run a customized &os; branch. Be paranoid about security, reducing as much as possible the possibility of compromise. Save space and inodes, as much as possible. This design relies on a single, read-only master template which is mounted into each jail and one read-write device per jail. A device can be a separate physical disc, a partition, or a vnode backed memory device. This example uses read-write nullfs mounts. The file system layout is as follows: The jails are based under the /home partition. Each jail will be mounted under the /home/j directory. The template for each jail and the read-only partition for all of the jails is /home/j/mroot. A blank directory will be created for each jail under the /home/j directory. Each jail will have a /s directory that will be linked to the read-write portion of the system. Each jail will have its own read-write system that is based upon /home/j/skel. The read-write portion of each jail will be created in /home/js. Creating the Template This section describes the steps needed to create the master template. It is recommended to first update the host &os; system to the latest -RELEASE branch using the instructions in . Additionally, this template uses the sysutils/cpdup package or port and portsnap will be used to download the &os; Ports Collection. First, create a directory structure for the read-only file system which will contain the &os; binaries for the jails. Then, change directory to the &os; source tree and install the read-only file system to the jail template: &prompt.root; mkdir /home/j /home/j/mroot &prompt.root; cd /usr/src &prompt.root; make installworld DESTDIR=/home/j/mroot Next, prepare a &os; Ports Collection for the jails as well as a &os; source tree, which is required for mergemaster: &prompt.root; cd /home/j/mroot &prompt.root; mkdir usr/ports &prompt.root; portsnap -p /home/j/mroot/usr/ports fetch extract &prompt.root; cpdup /usr/src /home/j/mroot/usr/src Create a skeleton for the read-write portion of the system: &prompt.root; mkdir /home/j/skel /home/j/skel/home /home/j/skel/usr-X11R6 /home/j/skel/distfiles &prompt.root; mv etc /home/j/skel &prompt.root; mv usr/local /home/j/skel/usr-local &prompt.root; mv tmp /home/j/skel &prompt.root; mv var /home/j/skel &prompt.root; mv root /home/j/skel Use mergemaster to install missing configuration files. Then, remove the extra directories that mergemaster creates: &prompt.root; mergemaster -t /home/j/skel/var/tmp/temproot -D /home/j/skel -i &prompt.root; cd /home/j/skel &prompt.root; rm -R bin boot lib libexec mnt proc rescue sbin sys usr dev Now, symlink the read-write file system to the read-only file system. Ensure that the symlinks are created in the correct s/ locations as the creation of directories in the wrong locations will cause the installation to fail. &prompt.root; cd /home/j/mroot &prompt.root; mkdir s &prompt.root; ln -s s/etc etc &prompt.root; ln -s s/home home &prompt.root; ln -s s/root root &prompt.root; ln -s s/usr-local usr/local &prompt.root; ln -s s/usr-X11R6 usr/X11R6 &prompt.root; ln -s s/distfiles usr/ports/distfiles &prompt.root; ln -s s/tmp tmp &prompt.root; ln -s s/var var As a last step, create a generic /home/j/skel/etc/make.conf containing this line: WRKDIRPREFIX?= /s/portbuild This makes it possible to compile &os; ports inside each jail. Remember that the ports directory is part of the read-only system. The custom path for WRKDIRPREFIX allows builds to be done in the read-write portion of every jail. Creating Jails The jail template can now be used to setup and configure the jails in /etc/rc.conf. This example demonstrates the creation of 3 jails: NS, MAIL and WWW. Add the following lines to /etc/fstab, so that the read-only template for the jails and the read-write space will be available in the respective jails: /home/j/mroot /home/j/ns nullfs ro 0 0 /home/j/mroot /home/j/mail nullfs ro 0 0 /home/j/mroot /home/j/www nullfs ro 0 0 /home/js/ns /home/j/ns/s nullfs rw 0 0 /home/js/mail /home/j/mail/s nullfs rw 0 0 /home/js/www /home/j/www/s nullfs rw 0 0 To prevent fsck from checking nullfs mounts during boot and dump from backing up the read-only nullfs mounts of the jails, the last two columns are both set to 0. Configure the jails in /etc/rc.conf: jail_enable="YES" jail_set_hostname_allow="NO" jail_list="ns mail www" jail_ns_hostname="ns.example.org" jail_ns_ip="192.168.3.17" jail_ns_rootdir="/usr/home/j/ns" jail_ns_devfs_enable="YES" jail_mail_hostname="mail.example.org" jail_mail_ip="192.168.3.18" jail_mail_rootdir="/usr/home/j/mail" jail_mail_devfs_enable="YES" jail_www_hostname="www.example.org" jail_www_ip="62.123.43.14" jail_www_rootdir="/usr/home/j/www" jail_www_devfs_enable="YES" The jail_name_rootdir variable is set to /usr/home instead of /home because the physical path of /home on a default &os; installation is /usr/home. The jail_name_rootdir variable must not be set to a path which includes a symbolic link, otherwise the jails will refuse to start. Create the required mount points for the read-only file system of each jail: &prompt.root; mkdir /home/j/ns /home/j/mail /home/j/www Install the read-write template into each jail using sysutils/cpdup: &prompt.root; mkdir /home/js &prompt.root; cpdup /home/j/skel /home/js/ns &prompt.root; cpdup /home/j/skel /home/js/mail &prompt.root; cpdup /home/j/skel /home/js/www In this phase, the jails are built and prepared to run. First, mount the required file systems for each jail, and then start them: &prompt.root; mount -a &prompt.root; service jail start The jails should be running now. To check if they have started correctly, use jls. Its output should be similar to the following: &prompt.root; jls JID IP Address Hostname Path 3 192.168.3.17 ns.example.org /home/j/ns 2 192.168.3.18 mail.example.org /home/j/mail 1 62.123.43.14 www.example.org /home/j/www At this point, it should be possible to log onto each jail, add new users, or configure daemons. The JID column indicates the jail identification number of each running jail. Use the following command to perform administrative tasks in the jail whose JID is 3: &prompt.root; jexec 3 tcsh Upgrading The design of this setup provides an easy way to upgrade existing jails while minimizing their downtime. Also, it provides a way to roll back to the older version should a problem occur. The first step is to upgrade the host system. Then, create a new temporary read-only template in /home/j/mroot2. &prompt.root; mkdir /home/j/mroot2 &prompt.root; cd /usr/src &prompt.root; make installworld DESTDIR=/home/j/mroot2 &prompt.root; cd /home/j/mroot2 &prompt.root; cpdup /usr/src usr/src &prompt.root; mkdir s The installworld creates a few unnecessary directories, which should be removed: &prompt.root; chflags -R 0 var &prompt.root; rm -R etc var root usr/local tmp Recreate the read-write symlinks for the master file system: &prompt.root; ln -s s/etc etc &prompt.root; ln -s s/root root &prompt.root; ln -s s/home home &prompt.root; ln -s ../s/usr-local usr/local &prompt.root; ln -s ../s/usr-X11R6 usr/X11R6 &prompt.root; ln -s s/tmp tmp &prompt.root; ln -s s/var var Next, stop the jails: &prompt.root; service jail stop Unmount the original file systems as the read-write systems are attached to the read-only system (/s): &prompt.root; umount /home/j/ns/s &prompt.root; umount /home/j/ns &prompt.root; umount /home/j/mail/s &prompt.root; umount /home/j/mail &prompt.root; umount /home/j/www/s &prompt.root; umount /home/j/www Move the old read-only file system and replace it with the new one. This will serve as a backup and archive of the old read-only file system should something go wrong. The naming convention used here corresponds to when a new read-only file system has been created. Move the original &os; Ports Collection over to the new file system to save some space and inodes: &prompt.root; cd /home/j &prompt.root; mv mroot mroot.20060601 &prompt.root; mv mroot2 mroot &prompt.root; mv mroot.20060601/usr/ports mroot/usr At this point the new read-only template is ready, so the only remaining task is to remount the file systems and start the jails: &prompt.root; mount -a &prompt.root; service jail start Use jls to check if the jails started correctly. Run mergemaster in each jail to update the configuration files. Managing Jails with <application>ezjail</application> Warren Block Originally contributed by Creating and managing multiple jails can quickly become tedious and error-prone. Dirk Engling's ezjail automates and greatly simplifies many jail tasks. A basejail is created as a template. Additional jails use &man.mount.nullfs.8; to share many of the basejail directories without using additional disk space. Each additional jail takes only a few megabytes of disk space before applications are installed. Upgrading the copy of the userland in the basejail automatically upgrades all of the other jails. Additional benefits and features are described in detail on the ezjail web site, . Installing <application>ezjail</application> Installing ezjail consists of adding a loopback interface for use in jails, installing the port or package, and enabling the service. To keep jail loopback traffic off the host's loopback network interface lo0, a second loopback interface is created by adding an entry to /etc/rc.conf: cloned_interfaces="${cloned_interfaces} lo1" The second loopback interface lo1 will be created when the system starts. It can also be created manually without a restart: &prompt.root; service netif cloneup Created clone interfaces: lo1. Jails can be allowed to use aliases of this secondary loopback interface without interfering with the host. Inside a jail, access to the loopback address 127.0.0.1 is redirected to the first IP address assigned to the jail. To make the jail loopback correspond with the new lo1 interface, that interface must be specified first in the list of interfaces and IP addresses given when creating a new jail. Give each jail a unique loopback address in the 127.0.0.0/8 netblock. Install sysutils/ezjail: &prompt.root; cd /usr/ports/sysutils/ezjail &prompt.root; make install clean Enable ezjail by adding this line to /etc/rc.conf: ezjail_enable="YES" The service will automatically start on system boot. It can be started immediately for the current session: &prompt.root; service ezjail start Initial Setup With ezjail installed, the basejail directory structure can be created and populated. This step is only needed once on the jail host computer. In both of these examples, causes the ports tree to be retrieved with &man.portsnap.8; into the basejail. That single copy of the ports directory will be shared by all the jails. Using a separate copy of the ports directory for jails isolates them from the host. The ezjail FAQ explains in more detail: . To Populate the Jail with &os;-RELEASE For a basejail based on the &os; RELEASE matching that of the host computer, use install. For example, on a host computer running &os; 10-STABLE, the latest RELEASE version of &os; -10 will be installed in the jail): &prompt.root; ezjail-admin install -p To Populate the Jail with <command>installworld</command> The basejail can be installed from binaries created by buildworld on the host with ezjail-admin update. In this example, &os; 10-STABLE has been built from source. The jail directories are created. Then installworld is executed, installing the host's /usr/obj into the basejail. &prompt.root; ezjail-admin update -i -p The host's /usr/src is used by default. A different source directory on the host can be specified with and a path, or set with ezjail_sourcetree in /usr/local/etc/ezjail.conf. The basejail's ports tree is shared by other jails. However, downloaded distfiles are stored in the jail that downloaded them. By default, these files are stored in /var/ports/distfiles within each jail. /var/ports inside each jail is also used as a work directory when building ports. Creating and Starting a New Jail New jails are created with ezjail-admin create. In these examples, the lo1 loopback interface is used as described above. Create and Start a New Jail Create the jail, specifying a name and the loopback and network interfaces to use, along with their IP addresses. In this example, the jail is named dnsjail. &prompt.root; ezjail-admin create dnsjail 'lo1|127.0.1.1,em0|192.168.1.50' Most network services run in jails without problems. A few network services, most notably &man.ping.8;, use raw network sockets. In jails, raw network sockets are disabled by default for security. Services that require them will not work. Occasionally, a jail genuinely needs raw sockets. For example, network monitoring applications often use &man.ping.8; to check the availability of other computers. When raw network sockets are actually needed in a jail, they can be enabled by editing the ezjail configuration file for the individual jail, /usr/local/etc/ezjail/jailname. Modify the parameters entry: export jail_jailname_parameters="allow.raw_sockets=1" Do not enable raw network sockets unless services in the jail actually require them. Start the jail: &prompt.root; ezjail-admin start dnsjail Use a console on the jail: &prompt.root; ezjail-admin console dnsjail The jail is operating and additional configuration can be completed. Typical settings added at this point include: Set the <systemitem class="username">root</systemitem> Password Connect to the jail and set the root user's password: &prompt.root; ezjail-admin console dnsjail &prompt.root; passwd Changing local password for root New Password: Retype New Password: Time Zone Configuration The jail's time zone can be set with &man.tzsetup.8;. To avoid spurious error messages, the &man.adjkerntz.8; entry in /etc/crontab can be commented or removed. This job attempts to update the computer's hardware clock with time zone changes, but jails are not allowed to access that hardware. <acronym>DNS</acronym> Servers Enter domain name server lines in /etc/resolv.conf so DNS works in the jail. Edit <filename>/etc/hosts</filename> Change the address and add the jail name to the localhost entries in /etc/hosts. Configure <filename>/etc/rc.conf</filename> Enter configuration settings in /etc/rc.conf. This is much like configuring a full computer. The host name and IP address are not set here. Those values are already provided by the jail configuration. With the jail configured, the applications for which the jail was created can be installed. Some ports must be built with special options to be used in a jail. For example, both of the network monitoring plugin packages net-mgmt/nagios-plugins and net-mgmt/monitoring-plugins have a JAIL option which must be enabled for them to work correctly inside a jail. Updating Jails Updating the Operating System Because the basejail's copy of the userland is shared by the other jails, updating the basejail automatically updates all of the other jails. Either source or binary updates can be used. To build the world from source on the host, then install it in the basejail, use: &prompt.root; ezjail-admin update -b If the world has already been compiled on the host, install it in the basejail with: &prompt.root; ezjail-admin update -i Binary updates use &man.freebsd-update.8;. These updates have the same limitations as if &man.freebsd-update.8; were being run directly. The most important one is that only -RELEASE versions of &os; are available with this method. To update the basejail to the latest patched release of the version of &os; on the host computer, use: &prompt.root; ezjail-admin update -r After updating the basejail, &man.mergemaster.8; can be run to update each jail's configuration files. How to use &man.mergemaster.8; depends on the purpose and trustworthiness of a jail. If a jail's services or users are not trusted, then &man.mergemaster.8; should only be run from within that jail: &man.mergemaster.8; on Untrusted Jail Delete the link from the jail's /usr/src into the basejail and create a new /usr/src in the jail as a mountpoint. Mount the host computer's /usr/src read-only on the jail's new /usr/src mountpoint: &prompt.root; rm /usr/jails/jailname/usr/src &prompt.root; mkdir /usr/jails/jailname/usr/src &prompt.root; mount -t nullfs -o ro /usr/src /usr/jails/jailname/usr/src Get a console in the jail: &prompt.root; ezjail-admin console jailname Inside the jail, run mergemaster. Then exit the jail console: &prompt.root; cd /usr/src &prompt.root; mergemaster -U &prompt.root; exit Finally, unmount the jail's /usr/src: &prompt.root; umount /usr/jails/jailname/usr/src &man.mergemaster.8; on Trusted Jail If the users and services in a jail are trusted, &man.mergemaster.8; can be run from the host: &prompt.root; mergemaster -U -D /usr/jails/jailname Updating Ports The ports tree in the basejail is shared by the other jails. Updating that copy of the ports tree gives the other jails the updated version also. The basejail ports tree is updated with &man.portsnap.8;: &prompt.root; ezjail-admin update -P Controlling Jails Stopping and Starting Jails ezjail automatically starts jails when the computer is started. Jails can be manually stopped and restarted with stop and start: &prompt.root; ezjail-admin stop sambajail Stopping jails: sambajail. By default, jails are started automatically when the host computer starts. Autostarting can be disabled with config: &prompt.root; ezjail-admin config -r norun seldomjail This takes effect the next time the host computer is started. A jail that is already running will not be stopped. Enabling autostart is very similar: &prompt.root; ezjail-admin config -r run oftenjail Archiving and Restoring Jails Use archive to create a .tar.gz archive of a jail. The file name is composed from the name of the jail and the current date. Archive files are written to the archive directory, /usr/jails/ezjail_archives. A different archive directory can be chosen by setting ezjail_archivedir in the configuration file. The archive file can be copied elsewhere as a backup, or an existing jail can be restored from it with restore. A new jail can be created from the archive, providing a convenient way to clone existing jails. Stop and archive a jail named wwwserver: &prompt.root; ezjail-admin stop wwwserver Stopping jails: wwwserver. &prompt.root; ezjail-admin archive wwwserver &prompt.root; ls /usr/jails/ezjail-archives/ wwwserver-201407271153.13.tar.gz Create a new jail named wwwserver-clone from the archive created in the previous step. Use the em1 interface and assign a new IP address to avoid conflict with the original: &prompt.root; ezjail-admin create -a /usr/jails/ezjail_archives/wwwserver-201407271153.13.tar.gz wwwserver-clone 'lo1|127.0.3.1,em1|192.168.1.51' Full Example: <application>BIND</application> in a Jail Putting the BIND DNS server in a jail improves security by isolating it. This example creates a simple caching-only name server. The jail will be called dns1. The jail will use IP address 192.168.1.240 on the host's re0 interface. The upstream ISP's DNS servers are at 10.0.0.62 and 10.0.0.61. The basejail has already been created and a ports tree installed. Running BIND in a Jail Create a cloned loopback interface by adding a line to /etc/rc.conf: cloned_interfaces="${cloned_interfaces} lo1" Immediately create the new loopback interface: &prompt.root; service netif cloneup Created clone interfaces: lo1. Create the jail: &prompt.root; ezjail-admin create dns1 'lo1|127.0.2.1,re0|192.168.1.240' Start the jail, connect to a console running on it, and perform some basic configuration: &prompt.root; ezjail-admin start dns1 &prompt.root; ezjail-admin console dns1 &prompt.root; passwd Changing local password for root New Password: Retype New Password: &prompt.root; tzsetup &prompt.root; sed -i .bak -e '/adjkerntz/ s/^/#/' /etc/crontab &prompt.root; sed -i .bak -e 's/127.0.0.1/127.0.2.1/g; s/localhost.my.domain/dns1.my.domain dns1/' /etc/hosts Temporarily set the upstream DNS servers in /etc/resolv.conf so ports can be downloaded: nameserver 10.0.0.62 nameserver 10.0.0.61 Still using the jail console, install dns/bind99. &prompt.root; cd /usr/ports/dns/bind99 &prompt.root; make -C /usr/ports/dns/bind99 install clean Configure the name server by editing /usr/local/etc/namedb/named.conf. Create an Access Control List (ACL) of addresses and networks that are permitted to send DNS queries to this name server. This section is added just before the options section already in the file: ... // or cause huge amounts of useless Internet traffic. acl "trusted" { 192.168.1.0/24; localhost; localnets; }; options { ... Use the jail IP address in the listen-on setting to accept DNS queries from other computers on the network: listen-on { 192.168.1.240; }; A simple caching-only DNS name server is created by changing the forwarders section. The original file contains: /* forwarders { 127.0.0.1; }; */ Uncomment the section by removing the /* and */ lines. Enter the IP addresses of the upstream DNS servers. Immediately after the forwarders section, add references to the trusted ACL defined earlier: forwarders { 10.0.0.62; 10.0.0.61; }; allow-query { any; }; allow-recursion { trusted; }; allow-query-cache { trusted; }; Enable the service in /etc/rc.conf: named_enable="YES" Start and test the name server: &prompt.root; service named start wrote key file "/usr/local/etc/namedb/rndc.key" Starting named. &prompt.root; /usr/local/bin/dig @192.168.1.240 freebsd.org A response that includes ;; Got answer; shows that the new DNS server is working. A long delay followed by a response including ;; connection timed out; no servers could be reached shows a problem. Check the configuration settings and make sure any local firewalls allow the new DNS access to the upstream DNS servers. The new DNS server can use itself for local name resolution, just like other local computers. Set the address of the DNS server in the client computer's /etc/resolv.conf: nameserver 192.168.1.240 A local DHCP server can be configured to provide this address for a local DNS server, providing automatic configuration on DHCP clients. Index: head/en_US.ISO8859-1/books/handbook/l10n/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/l10n/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/l10n/chapter.xml (revision 46052) @@ -1,1040 +1,1041 @@ + xml:id="l10n"> + Localization - <acronym>i18n</acronym>/<acronym>L10n</acronym> Usage and Setup AndreyChernovContributed by Michael C.WuRewritten by Synopsis &os; is a distributed project with users and contributors located all over the world. As such, &os; supports localization into many languages, allowing users to view, input, or process data in non-English languages. One can choose from most of the major languages, including, but not limited to: Chinese, German, Japanese, Korean, French, Russian, and Vietnamese. internationalization localization localization The term internationalization has been shortened to i18n, which represents the number of letters between the first and the last letters of internationalization. L10n uses the same naming scheme, but from localization. The i18n/L10n methods, protocols, and applications allow users to use languages of their choice. This chapter discusses the internationalization and localization features of &os;. After reading this chapter, you will know: How locale names are constructed. How to set the locale for a login shell. How to configure the console for non-English languages. How to configure Xorg for different languages. How to find i18n-compliant applications. Where to find more information for configuring specific languages. Before reading this chapter, you should: Know how to install additional third-party applications. Using Localization locale Localization settings are based on three components: the language code, country code, and encoding. Locale names are constructed from these parts as follows: LanguageCode_CountryCode.Encoding language codes country codes The LanguageCode and CountryCode are used to determine the country and the specific language variation. provides some examples of LanguageCode_CountryCode: Common Language and Country Codes LanguageCode_Country Code Description en_US English, United States ru_RU Russian, Russia zh_TW Traditional Chinese, Taiwan
A complete listing of available locales can be found by typing: &prompt.user; locale -a | more To determine the current locale setting: &prompt.user; locale encodings ASCII Language specific character sets, such as ISO8859-1, ISO8859-15, KOI8-R, and CP437, are described in &man.multibyte.3;. The active list of character sets can be found at the IANA Registry. Some languages, such as Chinese or Japanese, cannot be represented using ASCII characters and require an extended language encoding using either wide or multibyte characters. Examples of wide or multibyte encodings include EUC and Big5. Older applications may mistake these encodings for control characters while newer applications usually recognize these characters. Depending on the implementation, users may be required to compile an application with wide or multibyte character support, or to configure it correctly. &os; uses Xorg-compatible locale encodings. The rest of this section describes the various methods for configuring the locale on a &os; system. The next section will discuss the considerations for finding and compiling applications with i18n support. Setting Locale for Login Shell Locale settings are configured either in a user's ~/.login_conf or in the startup file of the user's shell: ~/.profile, ~/.bashrc, or ~/.cshrc. Two environment variables should be set: LANG, which sets the locale POSIX MIME MM_CHARSET, which sets the MIME character set used by applications In addition to the user's shell configuration, these variables should also be set for specific application configuration and Xorg configuration. locale login class Two methods are available for making the needed variable assignments: the login class method, which is the recommended method, and the startup file method. The next two sections demonstrate how to use both methods. Login Classes Method This first method is the recommended method as it assigns the required environment variables for locale name and MIME character sets for every possible shell. This setup can either be performed by each user or it can be configured for all users by the superuser. This minimal example sets both variables for Latin-1 encoding in the .login_conf of an individual user's home directory: me:\ :charset=ISO-8859-1:\ :lang=de_DE.ISO8859-1: Traditional Chinese BIG-5 encoding Here is an example of a user's ~/.login_conf that sets the variables for Traditional Chinese in BIG-5 encoding. More variables are needed because some applications do not correctly respect locale variables for Chinese, Japanese, and Korean: #Users who do not wish to use monetary units or time formats #of Taiwan can manually change each variable me:\ :lang=zh_TW.Big5:\ :setenv=LC_ALL=zh_TW.Big5:\ :setenv=LC_COLLATE=zh_TW.Big5:\ :setenv=LC_CTYPE=zh_TW.Big5:\ :setenv=LC_MESSAGES=zh_TW.Big5:\ :setenv=LC_MONETARY=zh_TW.Big5:\ :setenv=LC_NUMERIC=zh_TW.Big5:\ :setenv=LC_TIME=zh_TW.Big5:\ :charset=big5:\ :xmodifiers="@im=gcin": #Set gcin as the XIM Input Server Alternately, the superuser can configure all users of the system for localization. The following variables in /etc/login.conf are used to set the locale and MIME character set: language_name|Account Type Description:\ :charset=MIME_charset:\ :lang=locale_name:\ :tc=default: So, the previous Latin-1 example would look like this: german|German Users Accounts:\ :charset=ISO-8859-1:\ :lang=de_DE.ISO8859-1:\ :tc=default: See &man.login.conf.5; for more details about these variables. Whenever /etc/login.conf is edited, remember to execute the following command to update the capability database: &prompt.root; cap_mkdb /etc/login.conf Utilities Which Change Login Classes vipw In addition to manually editing /etc/login.conf, several utilities are available for setting the locale for newly created users. When using vipw to add new users, specify the language to set the locale: user:password:1111:11:language:0:0:User Name:/home/user:/bin/sh adduser login class When using adduser to add new users, the default language can be pre-configured for all new users or specified for an individual user. If all new users use the same language, set defaultclass = language in /etc/adduser.conf. To override this setting when creating a user, either input the required locale at this prompt: Enter login class: default []: or specify the locale to set when invoking adduser: &prompt.root; adduser -class language pw If pw is used to add new users, specify the locale as follows: &prompt.root; pw useradd user_name -L language Shell Startup File Method This second method is not recommended as each shell that is used requires manual configuration, where each shell has a different configuration file and differing syntax. As an example, to set the German language for the sh shell, these lines could be added to ~/.profile to set the shell for that user only. These lines could also be added to /etc/profile or /usr/share/skel/dot.profile to set that shell for all users: LANG=de_DE.ISO8859-1; export LANG MM_CHARSET=ISO-8859-1; export MM_CHARSET However, the name of the configuration file and the syntax used differs for the csh shell. These are the equivalent settings for ~/.csh.login, /etc/csh.login, or /usr/share/skel/dot.login: setenv LANG de_DE.ISO8859-1 setenv MM_CHARSET ISO-8859-1 To complicate matters, the syntax needed to configure Xorg in ~/.xinitrc also depends upon the shell. The first example is for the sh shell and the second is for the csh shell: LANG=de_DE.ISO8859-1; export LANG setenv LANG de_DE.ISO8859-1 Console Setup Several localized fonts are available for the console. To see a listing of available fonts, type ls /usr/share/syscons/fonts. To configure the console font, specify the font_name, without the .fnt suffix, in /etc/rc.conf: font8x16=font_name font8x14=font_name font8x8=font_name keymap screenmap The keymap and screenmap can be set by adding the following to /etc/rc.conf: scrnmap=screenmap_name keymap=keymap_name keychange="fkey_number sequence" To see the list of available screenmaps, type ls /usr/share/syscons/scrnmaps. Do not include the .scm suffix when specifying screenmap_name. A screenmap with a corresponding mapped font is usually needed as a workaround for expanding bit 8 to bit 9 on a VGA adapter's font character matrix so that letters are moved out of the pseudographics area if the screen font uses a bit 8 column. To see the list of available keymaps, type ls /usr/share/syscons/keymaps. When specifying the keymap_name, do not include the .kbd suffix. To test keymaps without rebooting, use &man.kbdmap.1;. The keychange entry is usually needed to program function keys to match the selected terminal type because function key sequences cannot be defined in the keymap. Next, set the correct console terminal type in /etc/ttys for all virtual terminal entries. summarizes the available terminal types.: Defined Terminal Types for Character Sets Character Set Terminal Type ISO8859-1 or ISO8859-15 cons25l1 ISO8859-2 cons25l2 ISO8859-7 cons25l7 KOI8-R cons25r KOI8-U cons25u CP437 (VGA default) cons25 US-ASCII cons25w
moused For languages with wide or multibyte characters, install a console for that language from the &os; Ports Collection. The available ports are summarized in . Once installed, refer to the port's pkg-message or man pages for configuration and usage instructions. Available Console From Ports Collection Language Port Location Traditional Chinese (BIG-5) chinese/big5con Chinese/Japanese/Korean chinese/cce Chinese/Japanese/Korean chinese/zhcon Japanese chinese/kon2 Japanese japanese/kon2-14dot Japanese japanese/kon2-16dot
If moused is enabled in /etc/rc.conf, additional configuration may be required. By default, the mouse cursor of the &man.syscons.4; driver occupies the 0xd0-0xd3 range in the character set. If the language uses this range, move the cursor's range by adding the following line to /etc/rc.conf: mousechar_start=3 Xorg Setup describes how to install and configure Xorg. When configuring Xorg for localization, additional fonts and input methods are available from the &os; Ports Collection. Application specific i18n settings such as fonts and menus can be tuned in ~/.Xresources and should allow users to view their selected language in graphical application menus. X Input Method (XIM) The X Input Method (XIM) protocol is an Xorg standard for inputting non-English characters. summarizes the input method applications which are available in the &os; Ports Collection. Additional Fcitx and Uim applications are also available. Available Input Methods Language Input Method Chinese chinese/gcin Chinese chinese/ibus-chewing Chinese chinese/ibus-pinyin Chinese chinese/oxim Chinese chinese/scim-fcitx Chinese chinese/scim-pinyin Chinese chinese/scim-tables Japanese japanese/ibus-anthy Japanese japanese/ibus-mozc Japanese japanese/ibus-skk Japanese japanese/im-ja Japanese japanese/kinput2 Japanese japanese/scim-anthy Japanese japanese/scim-canna Japanese japanese/scim-honoka Japanese japanese/scim-honoka-plugin-romkan Japanese japanese/scim-honoka-plugin-wnn Japanese japanese/scim-prime Japanese japanese/scim-skk Japanese japanese/scim-tables Japanese japanese/scim-tomoe Japanese japanese/scim-uim Japanese japanese/skkinput Japanese japanese/skkinput3 Japanese japanese/uim-anthy Korean korean/ibus-hangul Korean korean/imhangul Korean korean/nabi Korean korean/scim-hangul Korean korean/scim-tables Vietnamese vietnamese/xvnkb Vietnamese vietnamese/x-unikey
Finding <acronym>i18n</acronym> Applications i18n applications are programmed using i18n kits under libraries. These allow developers to write a simple file and translate displayed menus and texts to each language. The &os; Ports Collection contains many applications with built-in support for wide or multibyte characters for several languages. Such applications include i18n in their names for easy identification. However, they do not always support the language needed. Some applications can be compiled with the specific charset. This is usually done in the port's Makefile or by passing a value to configure. Refer to the i18n documentation in the respective &os; port's source for more information on how to determine the needed configure value or the port's Makefile to determine which compile options to use when building the port. Locale Configuration for Specific Languages This section provides configuration examples for localizing a &os; system for the Russian language. It then provides some additional resources for localizing other languages. Russian Language (KOI8-R Encoding) AndreyChernovOriginally contributed by localization Russian This section shows the specific settings needed to localize a &os; system for the Russian language. Refer to Using Localization for a more complete description of each type of setting. To set this locale for the login shell, add the following lines to each user's ~/.login_conf: me:My Account:\ :charset=KOI8-R:\ :lang=ru_RU.KOI8-R: To configure the console, add the following lines to /etc/rc.conf: keymap="ru.koi8-r" scrnmap="koi8-r2cp866" font8x16="cp866b-8x16" font8x14="cp866-8x14" font8x8="cp866-8x8" mousechar_start=3 For each ttyv entry in /etc/ttys, use cons25r as the terminal type. printers To configure printing, a special output filter is needed to convert from KOI8-R to CP866 since most printers with Russian characters come with hardware code page CP866. &os; includes a default filter for this purpose, /usr/libexec/lpr/ru/koi2alt. To use this filter, add this entry to /etc/printcap: lp|Russian local line printer:\ :sh:of=/usr/libexec/lpr/ru/koi2alt:\ :lp=/dev/lpt0:sd=/var/spool/output/lpd:lf=/var/log/lpd-errs: Refer to &man.printcap.5; for a more detailed explanation. To configure support for Russian filenames in mounted &ms-dos; file systems, include and the locale name when adding an entry to /etc/fstab: /dev/ad0s2 /dos/c msdos rw,-Lru_RU.KOI8-R 0 0 Refer to &man.mount.msdosfs.8; for more details. To configure Russian fonts for &xorg;, install the x11-fonts/xorg-fonts-cyrillic package. Then, check the "Files" section in /etc/X11/xorg.conf. The following line must be added before any other FontPath entries: FontPath "/usr/local/lib/X11/fonts/cyrillic" Additional Cyrillic fonts are available in the Ports Collection. To activate a Russian keyboard, add the following to the "Keyboard" section of /etc/xorg.conf: Option "XkbLayout" "us,ru" Option "XkbOptions" "grp:toggle" Make sure that XkbDisable is commented out in that file. For grp:toggle use Right Alt, for grp:ctrl_shift_toggle use CtrlShift. For grp:caps_toggle use CapsLock. The old CapsLock function is still available in LAT mode only using ShiftCapsLock. grp:caps_toggle does not work in &xorg; for some unknown reason. If the keyboard has &windows; keys, and some non-alphabetical keys are mapped incorrectly, add the following line to /etc/xorg.conf: Option "XkbVariant" ",winkeys" The Russian XKB keyboard may not work with non-localized applications. Minimally localized applications should call a XtSetLanguageProc (NULL, NULL, NULL); function early in the program. See http://koi8.pp.ru/xwin.html for more instructions on localizing Xorg applications. For more general information about KOI8-R encoding, refer to http://koi8.pp.ru/. Additional Language-Specific Resources This section lists some additional resources for configuring other locales. localization Traditional Chinese localization German localization Greek localization Japanese localization Korean Traditional Chinese for Taiwan The &os;-Taiwan Project has a Chinese HOWTO for &os; at http://netlab.cse.yzu.edu.tw/~statue/freebsd/zh-tut/. German Language Localization for All ISO 8859-1 Languages A tutorial on using umlauts on &os; is available in German at http://user.cs.tu-berlin.de/~eserte/FreeBSD/doc/umlaute/umlaute.html. Greek Language Localization A complete article on Greek support in &os; is available here, in Greek only, as part of the official &os; Greek documentation. Japanese and Korean Language Localization For Japanese, refer to http://www.jp.FreeBSD.org/, and for Korean, refer to http://www.kr.FreeBSD.org/. Non-English &os; Documentation Some &os; contributors have translated parts of the &os; documentation to other languages. They are available through links on the &os; web site or in /usr/share/doc. Index: head/en_US.ISO8859-1/books/handbook/mac/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/mac/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/mac/chapter.xml (revision 46052) @@ -1,1775 +1,1776 @@ + xml:id="mac"> + Mandatory Access Control TomRhodesWritten by Synopsis MAC Mandatory Access Control MAC &os; supports security extensions based on the &posix;.1e draft. These security mechanisms include file system Access Control Lists () and Mandatory Access Control (MAC). MAC allows access control modules to be loaded in order to implement security policies. Some modules provide protections for a narrow subset of the system, hardening a particular service. Others provide comprehensive labeled security across all subjects and objects. The mandatory part of the definition indicates that enforcement of controls is performed by administrators and the operating system. This is in contrast to the default security mechanism of Discretionary Access Control (DAC) where enforcement is left to the discretion of users. This chapter focuses on the MAC framework and the set of pluggable security policy modules &os; provides for enabling various security mechanisms. After reading this chapter, you will know: The terminology associated with the MAC framework. The capabilities of MAC security policy modules as well as the difference between a labeled and non-labeled policy. The considerations to take into account before configuring a system to use the MAC framework. Which MAC security policy modules are included in &os; and how to configure them. How to implement a more secure environment using the MAC framework. How to test the MAC configuration to ensure the framework has been properly implemented. Before reading this chapter, you should: Understand &unix; and &os; basics (). Have some familiarity with security and how it pertains to &os; (). Improper MAC configuration may cause loss of system access, aggravation of users, or inability to access the features provided by Xorg. More importantly, MAC should not be relied upon to completely secure a system. The MAC framework only augments an existing security policy. Without sound security practices and regular security checks, the system will never be completely secure. The examples contained within this chapter are for demonstration purposes and the example settings should not be implemented on a production system. Implementing any security policy takes a good deal of understanding, proper design, and thorough testing. While this chapter covers a broad range of security issues relating to the MAC framework, the development of new MAC security policy modules will not be covered. A number of security policy modules included with the MAC framework have specific characteristics which are provided for both testing and new module development. Refer to &man.mac.test.4;, &man.mac.stub.4; and &man.mac.none.4; for more information on these security policy modules and the various mechanisms they provide. Key Terms The following key terms are used when referring to the MAC framework: compartment: a set of programs and data to be partitioned or separated, where users are given explicit access to specific component of a system. A compartment represents a grouping, such as a work group, department, project, or topic. Compartments make it possible to implement a need-to-know-basis security policy. integrity: the level of trust which can be placed on data. As the integrity of the data is elevated, so does the ability to trust that data. level: the increased or decreased setting of a security attribute. As the level increases, its security is considered to elevate as well. label: a security attribute which can be applied to files, directories, or other items in the system. It could be considered a confidentiality stamp. When a label is placed on a file, it describes the security properties of that file and will only permit access by files, users, and resources with a similar security setting. The meaning and interpretation of label values depends on the policy configuration. Some policies treat a label as representing the integrity or secrecy of an object while other policies might use labels to hold rules for access. multilabel: this property is a file system option which can be set in single-user mode using &man.tunefs.8;, during boot using &man.fstab.5;, or during the creation of a new file system. This option permits an administrator to apply different MAC labels on different objects. This option only applies to security policy modules which support labeling. single label: a policy where the entire file system uses one label to enforce access control over the flow of data. Whenever is not set, all files will conform to the same label setting. object: an entity through which information flows under the direction of a subject. This includes directories, files, fields, screens, keyboards, memory, magnetic storage, printers or any other data storage or moving device. An object is a data container or a system resource. Access to an object effectively means access to its data. subject: any active entity that causes information to flow between objects such as a user, user process, or system process. On &os;, this is almost always a thread acting in a process on behalf of a user. policy: a collection of rules which defines how objectives are to be achieved. A policy usually documents how certain items are to be handled. This chapter considers a policy to be a collection of rules which controls the flow of data and information and defines who has access to that data and information. high-watermark: this type of policy permits the raising of security levels for the purpose of accessing higher level information. In most cases, the original level is restored after the process is complete. Currently, the &os; MAC framework does not include this type of policy. low-watermark: this type of policy permits lowering security levels for the purpose of accessing information which is less secure. In most cases, the original security level of the user is restored after the process is complete. The only security policy module in &os; to use this is &man.mac.lomac.4;. sensitivity: usually used when discussing Multilevel Security (MLS). A sensitivity level describes how important or secret the data should be. As the sensitivity level increases, so does the importance of the secrecy, or confidentiality, of the data. Understanding MAC Labels A MAC label is a security attribute which may be applied to subjects and objects throughout the system. When setting a label, the administrator must understand its implications in order to prevent unexpected or undesired behavior of the system. The attributes available on an object depend on the loaded policy module, as policy modules interpret their attributes in different ways. The security label on an object is used as a part of a security access control decision by a policy. With some policies, the label contains all of the information necessary to make a decision. In other policies, the labels may be processed as part of a larger rule set. There are two types of label policies: single label and multi label. By default, the system will use single label. The administrator should be aware of the pros and cons of each in order to implement policies which meet the requirements of the system's security model. A single label security policy only permits one label to be used for every subject or object. Since a single label policy enforces one set of access permissions across the entire system, it provides lower administration overhead, but decreases the flexibility of policies which support labeling. However, in many environments, a single label policy may be all that is required. A single label policy is somewhat similar to DAC as root configures the policies so that users are placed in the appropriate categories and access levels. A notable difference is that many policy modules can also restrict root. Basic control over objects will then be released to the group, but root may revoke or modify the settings at any time. When appropriate, a multi label policy can be set on a UFS file system by passing to &man.tunefs.8;. A multi label policy permits each subject or object to have its own independent MAC label. The decision to use a multi label or single label policy is only required for policies which implement the labeling feature, such as biba, lomac, and mls. Some policies, such as seeotheruids, portacl and partition, do not use labels at all. Using a multi label policy on a partition and establishing a multi label security model can increase administrative overhead as everything in that file system has a label. This includes directories, files, and even device nodes. The following command will set on the specified UFS file system. This may only be done in single-user mode and is not a requirement for the swap file system: &prompt.root; tunefs -l enable / Some users have experienced problems with setting the flag on the root partition. If this is the case, please review . Since the multi label policy is set on a per-file system basis, a multi label policy may not be needed if the file system layout is well designed. Consider an example security MAC model for a &os; web server. This machine uses the single label, biba/high, for everything in the default file systems. If the web server needs to run at biba/low to prevent write up capabilities, it could be installed to a separate UFS /usr/local file system set at biba/low. Label Configuration Virtually all aspects of label policy module configuration will be performed using the base system utilities. These commands provide a simple interface for object or subject configuration or the manipulation and verification of the configuration. All configuration may be done using setfmac, which is used to set MAC labels on system objects, and setpmac, which is used to set the labels on system subjects. For example, to set the biba MAC label to high on test: &prompt.root; setfmac biba/high test If the configuration is successful, the prompt will be returned without error. A common error is Permission denied which usually occurs when the label is being set or modified on a restricted object. Other conditions may produce different failures. For instance, the file may not be owned by the user attempting to relabel the object, the object may not exist, or the object may be read-only. A mandatory policy will not allow the process to relabel the file, maybe because of a property of the file, a property of the process, or a property of the proposed new label value. For example, if a user running at low integrity tries to change the label of a high integrity file, or a user running at low integrity tries to change the label of a low integrity file to a high integrity label, these operations will fail. The system administrator may use setpmac to override the policy module's settings by assigning a different label to the invoked process: &prompt.root; setfmac biba/high test Permission denied &prompt.root; setpmac biba/low setfmac biba/high test &prompt.root; getfmac test test: biba/high For currently running processes, such as sendmail, getpmac is usually used instead. This command takes a process ID (PID) in place of a command name. If users attempt to manipulate a file not in their access, subject to the rules of the loaded policy modules, the Operation not permitted error will be displayed. Predefined Labels A few &os; policy modules which support the labeling feature offer three predefined labels: low, equal, and high, where: low is considered the lowest label setting an object or subject may have. Setting this on objects or subjects blocks their access to objects or subjects marked high. equal sets the subject or object to be disabled or unaffected and should only be placed on objects considered to be exempt from the policy. high grants an object or subject the highest setting available in the Biba and MLS policy modules. Such policy modules include &man.mac.biba.4;, &man.mac.mls.4; and &man.mac.lomac.4;. Each of the predefined labels establishes a different information flow directive. Refer to the manual page of the module to determine the traits of the generic label configurations. Numeric Labels The Biba and MLS policy modules support a numeric label which may be set to indicate the precise level of hierarchical control. This numeric level is used to partition or sort information into different groups of classification, only permitting access to that group or a higher group level. For example: biba/10:2+3+6(5:2+3-20:2+3+4+5+6) may be interpreted as Biba Policy Label/Grade 10:Compartments 2, 3 and 6: (grade 5 ...) In this example, the first grade would be considered the effective grade with effective compartments, the second grade is the low grade, and the last one is the high grade. In most configurations, such fine-grained settings are not needed as they are considered to be advanced configurations. System objects only have a current grade and compartment. System subjects reflect the range of available rights in the system, and network interfaces, where they are used for access control. The grade and compartments in a subject and object pair are used to construct a relationship known as dominance, in which a subject dominates an object, the object dominates the subject, neither dominates the other, or both dominate each other. The both dominate case occurs when the two labels are equal. Due to the information flow nature of Biba, a user has rights to a set of compartments that might correspond to projects, but objects also have a set of compartments. Users may have to subset their rights using su or setpmac in order to access objects in a compartment from which they are not restricted. User Labels Users are required to have labels so that their files and processes properly interact with the security policy defined on the system. This is configured in /etc/login.conf using login classes. Every policy module that uses labels will implement the user class setting. To set the user class default label which will be enforced by MAC, add a entry. An example entry containing every policy module is displayed below. Note that in a real configuration, the administrator would never enable every policy module. It is recommended that the rest of this chapter be reviewed before any configuration is implemented. default:\ :copyright=/etc/COPYRIGHT:\ :welcome=/etc/motd:\ :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\ :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:\ :manpath=/usr/share/man /usr/local/man:\ :nologin=/usr/sbin/nologin:\ :cputime=1h30m:\ :datasize=8M:\ :vmemoryuse=100M:\ :stacksize=2M:\ :memorylocked=4M:\ :memoryuse=8M:\ :filesize=8M:\ :coredumpsize=8M:\ :openfiles=24:\ :maxproc=32:\ :priority=0:\ :requirehome:\ :passwordtime=91d:\ :umask=022:\ :ignoretime@:\ :label=partition/13,mls/5,biba/10(5-15),lomac/10[2]: While users can not modify the default value, they may change their label after they login, subject to the constraints of the policy. The example above tells the Biba policy that a process's minimum integrity is 5, its maximum is 15, and the default effective label is 10. The process will run at 10 until it chooses to change label, perhaps due to the user using setpmac, which will be constrained by Biba to the configured range. After any change to login.conf, the login class capability database must be rebuilt using cap_mkdb. Many sites have a large number of users requiring several different user classes. In depth planning is required as this can become difficult to manage. Network Interface Labels Labels may be set on network interfaces to help control the flow of data across the network. Policies using network interface labels function in the same way that policies function with respect to objects. Users at high settings in Biba, for example, will not be permitted to access network interfaces with a label of low. When setting the MAC label on network interfaces, may be passed to ifconfig: &prompt.root; ifconfig bge0 maclabel biba/equal This example will set the MAC label of biba/equal on the bge0 interface. When using a setting similar to biba/high(low-high), the entire label should be quoted to prevent an error from being returned. Each policy module which supports labeling has a tunable which may be used to disable the MAC label on network interfaces. Setting the label to will have a similar effect. Review the output of sysctl, the policy manual pages, and the information in the rest of this chapter for more information on those tunables. Planning the Security Configuration Before implementing any MAC policies, a planning phase is recommended. During the planning stages, an administrator should consider the implementation requirements and goals, such as: How to classify information and resources available on the target systems. Which information or resources to restrict access to along with the type of restrictions that should be applied. Which MAC modules will be required to achieve this goal. A trial run of the trusted system and its configuration should occur before a MAC implementation is used on production systems. Since different environments have different needs and requirements, establishing a complete security profile will decrease the need of changes once the system goes live. Consider how the MAC framework augments the security of the system as a whole. The various security policy modules provided by the MAC framework could be used to protect the network and file systems or to block users from accessing certain ports and sockets. Perhaps the best use of the policy modules is to load several security policy modules at a time in order to provide a MLS environment. This approach differs from a hardening policy, which typically hardens elements of a system which are used only for specific purposes. The downside to MLS is increased administrative overhead. The overhead is minimal when compared to the lasting effect of a framework which provides the ability to pick and choose which policies are required for a specific configuration and which keeps performance overhead down. The reduction of support for unneeded policies can increase the overall performance of the system as well as offer flexibility of choice. A good implementation would consider the overall security requirements and effectively implement the various security policy modules offered by the framework. A system utilizing MAC guarantees that a user will not be permitted to change security attributes at will. All user utilities, programs, and scripts must work within the constraints of the access rules provided by the selected security policy modules and control of the MAC access rules is in the hands of the system administrator. It is the duty of the system administrator to carefully select the correct security policy modules. For an environment that needs to limit access control over the network, the &man.mac.portacl.4;, &man.mac.ifoff.4;, and &man.mac.biba.4; policy modules make good starting points. For an environment where strict confidentiality of file system objects is required, consider the &man.mac.bsdextended.4; and &man.mac.mls.4; policy modules. Policy decisions could be made based on network configuration. If only certain users should be permitted access to &man.ssh.1;, the &man.mac.portacl.4; policy module is a good choice. In the case of file systems, access to objects might be considered confidential to some users, but not to others. As an example, a large development team might be broken off into smaller projects where developers in project A might not be permitted to access objects written by developers in project B. Yet both projects might need to access objects created by developers in project C. Using the different security policy modules provided by the MAC framework, users could be divided into these groups and then given access to the appropriate objects. Each security policy module has a unique way of dealing with the overall security of a system. Module selection should be based on a well thought out security policy which may require revision and reimplementation. Understanding the different security policy modules offered by the MAC framework will help administrators choose the best policies for their situations. The rest of this chapter covers the available modules, describes their use and configuration, and in some cases, provides insight on applicable situations. Implementing MAC is much like implementing a firewall since care must be taken to prevent being completely locked out of the system. The ability to revert back to a previous configuration should be considered and the implementation of MAC over a remote connection should be done with extreme caution. Available MAC Policies Beginning with &os; 8.0, the default &os; kernel includes options MAC. This means that every module included with the MAC framework can be loaded with kldload as a run-time kernel module. After testing the module, add the module name to /boot/loader.conf so that it will load during boot. Each module also provides a kernel option for those administrators who choose to compile their own custom kernel. &os; includes a group of policies that will cover most security requirements. Each policy is summarized below. The last three policies support integer settings in place of the three default labels. The MAC See Other UIDs Policy MAC See Other UIDs Policy Module name: mac_seeotheruids.ko Kernel configuration line: options MAC_SEEOTHERUIDS Boot option: mac_seeotheruids_load="YES" The &man.mac.seeotheruids.4; module extends the security.bsd.see_other_uids and security.bsd.see_other_gids sysctl tunables. This option does not require any labels to be set before configuration and can operate transparently with other modules. After loading the module, the following sysctl tunables may be used to control its features: security.mac.seeotheruids.enabled enables the module and implements the default settings which deny users the ability to view processes and sockets owned by other users. security.mac.seeotheruids.specificgid_enabled allows specified groups to be exempt from this policy. To exempt specific groups, use the security.mac.seeotheruids.specificgid=XXX sysctl tunable, replacing XXX with the numeric group ID to be exempted. security.mac.seeotheruids.primarygroup_enabled is used to exempt specific primary groups from this policy. When using this tunable, security.mac.seeotheruids.specificgid_enabled may not be set. The MAC BSD Extended Policy MAC File System Firewall Policy Module name: mac_bsdextended.ko Kernel configuration line: options MAC_BSDEXTENDED Boot option: mac_bsdextended_load="YES" The &man.mac.bsdextended.4; module enforces a file system firewall. It provides an extension to the standard file system permissions model, permitting an administrator to create a firewall-like ruleset to protect files, utilities, and directories in the file system hierarchy. When access to a file system object is attempted, the list of rules is iterated until either a matching rule is located or the end is reached. This behavior may be changed using security.mac.bsdextended.firstmatch_enabled. Similar to other firewall modules in &os;, a file containing the access control rules can be created and read by the system at boot time using an &man.rc.conf.5; variable. The rule list may be entered using &man.ugidfw.8; which has a syntax similar to &man.ipfw.8;. More tools can be written by using the functions in the &man.libugidfw.3; library. After the &man.mac.bsdextended.4; module has been loaded, the following command may be used to list the current rule configuration: &prompt.root; ugidfw list 0 slots, 0 rules By default, no rules are defined and everything is completely accessible. To create a rule which blocks all access by users but leaves root unaffected: &prompt.root; ugidfw add subject not uid root new object not uid root mode n While this rule is simple to implement, it is a very bad idea as it blocks all users from issuing any commands. A more realistic example blocks user1 all access, including directory listings, to user2's home directory: &prompt.root; ugidfw set 2 subject uid user1 object uid user2 mode n &prompt.root; ugidfw set 3 subject uid user1 object gid user2 mode n Instead of user1, could be used in order to enforce the same access restrictions for all users. However, the root user is unaffected by these rules. Extreme caution should be taken when working with this module as incorrect use could block access to certain parts of the file system. The MAC Interface Silencing Policy MAC Interface Silencing Policy Module name: mac_ifoff.ko Kernel configuration line: options MAC_IFOFF Boot option: mac_ifoff_load="YES" The &man.mac.ifoff.4; module is used to disable network interfaces on the fly and to keep network interfaces from being brought up during system boot. It does not use labels and does not depend on any other MAC modules. Most of this module's control is performed through these sysctl tunables: security.mac.ifoff.lo_enabled enables or disables all traffic on the loopback, &man.lo.4;, interface. security.mac.ifoff.bpfrecv_enabled enables or disables all traffic on the Berkeley Packet Filter interface, &man.bpf.4;. security.mac.ifoff.other_enabled enables or disables traffic on all other interfaces. One of the most common uses of &man.mac.ifoff.4; is network monitoring in an environment where network traffic should not be permitted during the boot sequence. Another use would be to write a script which uses an application such as security/aide to automatically block network traffic if it finds new or altered files in protected directories. The MAC Port Access Control List Policy MAC Port Access Control List Policy Module name: mac_portacl.ko Kernel configuration line: MAC_PORTACL Boot option: mac_portacl_load="YES" The &man.mac.portacl.4; module is used to limit binding to local TCP and UDP ports, making it possible to allow non-root users to bind to specified privileged ports below 1024. Once loaded, this module enables the MAC policy on all sockets. The following tunables are available: security.mac.portacl.enabled enables or disables the policy completely. security.mac.portacl.port_high sets the highest port number that &man.mac.portacl.4; protects. security.mac.portacl.suser_exempt, when set to a non-zero value, exempts the root user from this policy. security.mac.portacl.rules specifies the policy as a text string of the form rule[,rule,...], with as many rules as needed, and where each rule is of the form idtype:id:protocol:port. The idtype is either uid or gid. The protocol parameter can be tcp or udp. The port parameter is the port number to allow the specified user or group to bind to. Only numeric values can be used for the user ID, group ID, and port parameters. By default, ports below 1024 can only be used by privileged processes which run as root. For &man.mac.portacl.4; to allow non-privileged processes to bind to ports below 1024, set the following tunables as follows: &prompt.root; sysctl security.mac.portacl.port_high=1023 &prompt.root; sysctl net.inet.ip.portrange.reservedlow=0 &prompt.root; sysctl net.inet.ip.portrange.reservedhigh=0 To prevent the root user from being affected by this policy, set security.mac.portacl.suser_exempt to a non-zero value. &prompt.root; sysctl security.mac.portacl.suser_exempt=1 To allow the www user with UID 80 to bind to port 80 without ever needing root privilege: &prompt.root; sysctl security.mac.portacl.rules=uid:80:tcp:80 This next example permits the user with the UID of 1001 to bind to TCP ports 110 (POP3) and 995 (POP3s): &prompt.root; sysctl security.mac.portacl.rules=uid:1001:tcp:110,uid:1001:tcp:995 The MAC Partition Policy MAC Process Partition Policy Module name: mac_partition.ko Kernel configuration line: options MAC_PARTITION Boot option: mac_partition_load="YES" The &man.mac.partition.4; policy drops processes into specific partitions based on their MAC label. Most configuration for this policy is done using &man.setpmac.8;. One sysctl tunable is available for this policy: security.mac.partition.enabled enables the enforcement of MAC process partitions. When this policy is enabled, users will only be permitted to see their processes, and any others within their partition, but will not be permitted to work with utilities outside the scope of this partition. For instance, a user in the insecure class will not be permitted to access top as well as many other commands that must spawn a process. This example adds top to the label set on users in the insecure class. All processes spawned by users in the insecure class will stay in the partition/13 label. &prompt.root; setpmac partition/13 top This command displays the partition label and the process list: &prompt.root; ps Zax This command displays another user's process partition label and that user's currently running processes: &prompt.root; ps -ZU trhodes Users can see processes in root's label unless the &man.mac.seeotheruids.4; policy is loaded. The MAC Multi-Level Security Module MAC Multi-Level Security Policy Module name: mac_mls.ko Kernel configuration line: options MAC_MLS Boot option: mac_mls_load="YES" The &man.mac.mls.4; policy controls access between subjects and objects in the system by enforcing a strict information flow policy. In MLS environments, a clearance level is set in the label of each subject or object, along with compartments. Since these clearance levels can reach numbers greater than several thousand, it would be a daunting task to thoroughly configure every subject or object. To ease this administrative overhead, three labels are included in this policy: mls/low, mls/equal, and mls/high, where: Anything labeled with mls/low will have a low clearance level and not be permitted to access information of a higher level. This label also prevents objects of a higher clearance level from writing or passing information to a lower level. mls/equal should be placed on objects which should be exempt from the policy. mls/high is the highest level of clearance possible. Objects assigned this label will hold dominance over all other objects in the system; however, they will not permit the leaking of information to objects of a lower class. MLS provides: A hierarchical security level with a set of non-hierarchical categories. Fixed rules of no read up, no write down. This means that a subject can have read access to objects on its own level or below, but not above. Similarly, a subject can have write access to objects on its own level or above, but not beneath. Secrecy, or the prevention of inappropriate disclosure of data. A basis for the design of systems that concurrently handle data at multiple sensitivity levels without leaking information between secret and confidential. The following sysctl tunables are available: security.mac.mls.enabled is used to enable or disable the MLS policy. security.mac.mls.ptys_equal labels all &man.pty.4; devices as mls/equal during creation. security.mac.mls.revocation_enabled revokes access to objects after their label changes to a label of a lower grade. security.mac.mls.max_compartments sets the maximum number of compartment levels allowed on a system. To manipulate MLS labels, use &man.setfmac.8;. To assign a label to an object: &prompt.root; setfmac mls/5 test To get the MLS label for the file test: &prompt.root; getfmac test Another approach is to create a master policy file in /etc/ which specifies the MLS policy information and to feed that file to setfmac. When using the MLS policy module, an administrator plans to control the flow of sensitive information. The default block read up block write down sets everything to a low state. Everything is accessible and an administrator slowly augments the confidentiality of the information. Beyond the three basic label options, an administrator may group users and groups as required to block the information flow between them. It might be easier to look at the information in clearance levels using descriptive words, such as classifications of Confidential, Secret, and Top Secret. Some administrators instead create different groups based on project levels. Regardless of the classification method, a well thought out plan must exist before implementing a restrictive policy. Some example situations for the MLS policy module include an e-commerce web server, a file server holding critical company information, and financial institution environments. The MAC Biba Module MAC Biba Integrity Policy Module name: mac_biba.ko Kernel configuration line: options MAC_BIBA Boot option: mac_biba_load="YES" The &man.mac.biba.4; module loads the MAC Biba policy. This policy is similar to the MLS policy with the exception that the rules for information flow are slightly reversed. This is to prevent the downward flow of sensitive information whereas the MLS policy prevents the upward flow of sensitive information. In Biba environments, an integrity label is set on each subject or object. These labels are made up of hierarchical grades and non-hierarchical components. As a grade ascends, so does its integrity. Supported labels are biba/low, biba/equal, and biba/high, where: biba/low is considered the lowest integrity an object or subject may have. Setting this on objects or subjects blocks their write access to objects or subjects marked as biba/high, but will not prevent read access. biba/equal should only be placed on objects considered to be exempt from the policy. biba/high permits writing to objects set at a lower label, but does not permit reading that object. It is recommended that this label be placed on objects that affect the integrity of the entire system. Biba provides: Hierarchical integrity levels with a set of non-hierarchical integrity categories. Fixed rules are no write up, no read down, the opposite of MLS. A subject can have write access to objects on its own level or below, but not above. Similarly, a subject can have read access to objects on its own level or above, but not below. Integrity by preventing inappropriate modification of data. Integrity levels instead of MLS sensitivity levels. The following tunables can be used to manipulate the Biba policy: security.mac.biba.enabled is used to enable or disable enforcement of the Biba policy on the target machine. security.mac.biba.ptys_equal is used to disable the Biba policy on &man.pty.4; devices. security.mac.biba.revocation_enabled forces the revocation of access to objects if the label is changed to dominate the subject. To access the Biba policy setting on system objects, use setfmac and getfmac: &prompt.root; setfmac biba/low test &prompt.root; getfmac test test: biba/low Integrity, which is different from sensitivity, is used to guarantee that information is not manipulated by untrusted parties. This includes information passed between subjects and objects. It ensures that users will only be able to modify or access information they have been given explicit access to. The &man.mac.biba.4; security policy module permits an administrator to configure which files and programs a user may see and invoke while assuring that the programs and files are trusted by the system for that user. During the initial planning phase, an administrator must be prepared to partition users into grades, levels, and areas. The system will default to a high label once this policy module is enabled, and it is up to the administrator to configure the different grades and levels for users. Instead of using clearance levels, a good planning method could include topics. For instance, only allow developers modification access to the source code repository, source code compiler, and other development utilities. Other users would be grouped into other categories such as testers, designers, or end users and would only be permitted read access. A lower integrity subject is unable to write to a higher integrity subject and a higher integrity subject cannot list or read a lower integrity object. Setting a label at the lowest possible grade could make it inaccessible to subjects. Some prospective environments for this security policy module would include a constrained web server, a development and test machine, and a source code repository. A less useful implementation would be a personal workstation, a machine used as a router, or a network firewall. The MAC Low-watermark Module MAC LOMAC Module name: mac_lomac.ko Kernel configuration line: options MAC_LOMAC Boot option: mac_lomac_load="YES" Unlike the MAC Biba policy, the &man.mac.lomac.4; policy permits access to lower integrity objects only after decreasing the integrity level to not disrupt any integrity rules. The Low-watermark integrity policy works almost identically to Biba, with the exception of using floating labels to support subject demotion via an auxiliary grade compartment. This secondary compartment takes the form [auxgrade]. When assigning a policy with an auxiliary grade, use the syntax lomac/10[2], where 2 is the auxiliary grade. This policy relies on the ubiquitous labeling of all system objects with integrity labels, permitting subjects to read from low integrity objects and then downgrading the label on the subject to prevent future writes to high integrity objects using [auxgrade]. The policy may provide greater compatibility and require less initial configuration than Biba. Like the Biba and MLS policies, setfmac and setpmac are used to place labels on system objects: &prompt.root; setfmac /usr/home/trhodes lomac/high[low] &prompt.root; getfmac /usr/home/trhodes lomac/high[low] The auxiliary grade low is a feature provided only by the MAC LOMAC policy. User Lock Down This example considers a relatively small storage system with fewer than fifty users. Users will have login capabilities and are permitted to store data and access resources. For this scenario, the &man.mac.bsdextended.4; and &man.mac.seeotheruids.4; policy modules could co-exist and block access to system objects while hiding user processes. Begin by adding the following line to /boot/loader.conf: mac_seeotheruids_load="YES" The &man.mac.bsdextended.4; security policy module may be activated by adding this line to /etc/rc.conf: ugidfw_enable="YES" Default rules stored in /etc/rc.bsdextended will be loaded at system initialization. However, the default entries may need modification. Since this machine is expected only to service users, everything may be left commented out except the last two lines in order to force the loading of user owned system objects by default. Add the required users to this machine and reboot. For testing purposes, try logging in as a different user across two consoles. Run ps aux to see if processes of other users are visible. Verify that running &man.ls.1; on another user's home directory fails. Do not try to test with the root user unless the specific sysctls have been modified to block super user access. When a new user is added, their &man.mac.bsdextended.4; rule will not be in the ruleset list. To update the ruleset quickly, unload the security policy module and reload it again using &man.kldunload.8; and &man.kldload.8;. Nagios in a MAC Jail Nagios in a MAC Jail This section demonstrates the steps that are needed to implement the Nagios network monitoring system in a MAC environment. This is meant as an example which still requires the administrator to test that the implemented policy meets the security requirements of the network before using in a production environment. This example requires to be set on each file system. It also assumes that net-mgmt/nagios-plugins, net-mgmt/nagios, and www/apache22 are all installed, configured, and working correctly before attempting the integration into the MAC framework. Create an Insecure User Class Begin the procedure by adding the following user class to /etc/login.conf: insecure:\ :copyright=/etc/COPYRIGHT:\ :welcome=/etc/motd:\ :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\ :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin :manpath=/usr/share/man /usr/local/man:\ :nologin=/usr/sbin/nologin:\ :cputime=1h30m:\ :datasize=8M:\ :vmemoryuse=100M:\ :stacksize=2M:\ :memorylocked=4M:\ :memoryuse=8M:\ :filesize=8M:\ :coredumpsize=8M:\ :openfiles=24:\ :maxproc=32:\ :priority=0:\ :requirehome:\ :passwordtime=91d:\ :umask=022:\ :ignoretime@:\ :label=biba/10(10-10): Then, add the following line to the default user class section: :label=biba/high: Save the edits and issue the following command to rebuild the database: &prompt.root; cap_mkdb /etc/login.conf Configure Users Set the root user to the default class using: &prompt.root; pw usermod root -L default All user accounts that are not root will now require a login class. The login class is required, otherwise users will be refused access to common commands. The following sh script should do the trick: &prompt.root; for x in `awk -F: '($3 >= 1001) && ($3 != 65534) { print $1 }' \ /etc/passwd`; do pw usermod $x -L default; done; Next, drop the nagios and www accounts into the insecure class: &prompt.root; pw usermod nagios -L insecure &prompt.root; pw usermod www -L insecure Create the Contexts File A contexts file should now be created as /etc/policy.contexts: # This is the default BIBA policy for this system. # System: /var/run(/.*)? biba/equal /dev/(/.*)? biba/equal /var biba/equal /var/spool(/.*)? biba/equal /var/log(/.*)? biba/equal /tmp(/.*)? biba/equal /var/tmp(/.*)? biba/equal /var/spool/mqueue biba/equal /var/spool/clientmqueue biba/equal # For Nagios: /usr/local/etc/nagios(/.*)? biba/10 /var/spool/nagios(/.*)? biba/10 # For apache /usr/local/etc/apache(/.*)? biba/10 This policy enforces security by setting restrictions on the flow of information. In this specific configuration, users, including root, should never be allowed to access Nagios. Configuration files and processes that are a part of Nagios will be completely self contained or jailed. This file will be read after running setfsmac on every file system. This example sets the policy on the root file system: &prompt.root; setfsmac -ef /etc/policy.contexts / Next, add these edits to the main section of /etc/mac.conf: default_labels file ?biba default_labels ifnet ?biba default_labels process ?biba default_labels socket ?biba Loader Configuration To finish the configuration, add the following lines to /boot/loader.conf: mac_biba_load="YES" mac_seeotheruids_load="YES" security.mac.biba.trust_all_interfaces=1 And the following line to the network card configuration stored in /etc/rc.conf. If the primary network configuration is done via DHCP, this may need to be configured manually after every system boot: maclabel biba/equal Testing the Configuration MAC Configuration Testing First, ensure that the web server and Nagios will not be started on system initialization and reboot. Ensure that root cannot access any of the files in the Nagios configuration directory. If root can list the contents of /var/spool/nagios, something is wrong. Instead, a permission denied error should be returned. If all seems well, Nagios, Apache, and Sendmail can now be started: &prompt.root; cd /etc/mail && make stop && \ setpmac biba/equal make start && setpmac biba/10\(10-10\) apachectl start && \ setpmac biba/10\(10-10\) /usr/local/etc/rc.d/nagios.sh forcestart Double check to ensure that everything is working properly. If not, check the log files for error messages. If needed, use &man.sysctl.8; to disable the &man.mac.biba.4; security policy module and try starting everything again as usual. The root user can still change the security enforcement and edit its configuration files. The following command will permit the degradation of the security policy to a lower grade for a newly spawned shell: &prompt.root; setpmac biba/10 csh To block this from happening, force the user into a range using &man.login.conf.5;. If &man.setpmac.8; attempts to run a command outside of the compartment's range, an error will be returned and the command will not be executed. In this case, set root to biba/high(high-high). Troubleshooting the MAC Framework MAC Troubleshooting This section discusses common configuration errors and how to resolve them. The flag does not stay enabled on the root (/) partition: The following steps may resolve this transient error: Edit /etc/fstab and set the root partition to for read-only. Reboot into single user mode. Run tunefs on /. Reboot the system. Run mount / and change the back to in /etc/fstab and reboot the system again. Double-check the output from mount to ensure that has been properly set on the root file system. After establishing a secure environment with MAC, Xorg no longer starts: This could be caused by the MAC partition policy or by a mislabeling in one of the MAC labeling policies. To debug, try the following: Check the error message. If the user is in the insecure class, the partition policy may be the culprit. Try setting the user's class back to the default class and rebuild the database with cap_mkdb. If this does not alleviate the problem, go to step two. Double-check that the label policies are set correctly for the user, Xorg, and the /dev entries. If neither of these resolve the problem, send the error message and a description of the environment to the &a.questions;. The _secure_path: unable to stat .login_conf error appears: This error can appear when a user attempts to switch from the root user to another user in the system. This message usually occurs when the user has a higher label setting than that of the user they are attempting to become. For instance, if joe has a default label of and root has a label of , root cannot view joe's home directory. This will happen whether or not root has used su to become joe as the Biba integrity model will not permit root to view objects set at a lower integrity level. The system no longer recognizes root: When this occurs, whoami returns 0 and su returns who are you?. This can happen if a labeling policy has been disabled by &man.sysctl.8; or the policy module was unloaded. If the policy is disabled, the login capabilities database needs to be reconfigured. Double check /etc/login.conf to ensure that all options have been removed and rebuild the database with cap_mkdb. This may also happen if a policy restricts access to master.passwd. This is usually caused by an administrator altering the file under a label which conflicts with the general policy being used by the system. In these cases, the user information would be read by the system and access would be blocked as the file has inherited the new label. Disable the policy using &man.sysctl.8; and everything should return to normal. Index: head/en_US.ISO8859-1/books/handbook/mail/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/mail/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/mail/chapter.xml (revision 46052) @@ -1,1914 +1,1915 @@ - Electronic Mail + xml:id="mail"> + + Electronic Mail BillLloydOriginal work by JimMockRewritten by Synopsis email Electronic Mail, better known as email, is one of the most widely used forms of communication today. This chapter provides a basic introduction to running a mail server on &os;, as well as an introduction to sending and receiving email using &os;. For more complete coverage of this subject, refer to the books listed in . After reading this chapter, you will know: Which software components are involved in sending and receiving electronic mail. Where basic sendmail configuration files are located in &os;. The difference between remote and local mailboxes. How to block spammers from illegally using a mail server as a relay. How to install and configure an alternate Mail Transfer Agent, replacing sendmail. How to troubleshoot common mail server problems. How to set up the system to send mail only. How to use mail with a dialup connection. How to configure SMTP authentication for added security. How to install and use a Mail User Agent, such as mutt, to send and receive email. How to download mail from a remote POP or IMAP server. How to automatically apply filters and rules to incoming email. Before reading this chapter, you should: Properly set up a network connection (). Properly set up the DNS information for a mail host (). Know how to install additional third-party software (). Mail Components POP IMAP DNS mail server daemons Sendmail mail server daemons Postfix mail server daemons qmail mail server daemons Exim email receiving MX record mail host There are five major parts involved in an email exchange: the Mail User Agent (MUA), the Mail Transfer Agent (MTA), a mail host, a remote or local mailbox, and DNS. This section provides an overview of these components. Mail User Agent (MUA) The Mail User Agent (MUA) is an application which is used to compose, send, and receive emails. This application can be a command line program, such as the built-in mail utility or a third-party application from the Ports Collection, such as mutt, alpine, or elm. Dozens of graphical programs are also available in the Ports Collection, including Claws Mail, Evolution, and Thunderbird. Some organizations provide a web mail program which can be accessed through a web browser. More information about installing and using a MUA on &os; can be found in . Mail Transfer Agent (MTA) The Mail Transfer Agent (MTA) is responsible for receiving incoming mail and delivering outgoing mail. &os; ships with Sendmail as the default MTA, but it also supports numerous other mail server daemons, including Exim, Postfix, and qmail. Sendmail configuration is described in . If another MTA is installed using the Ports Collection, refer to its post-installation message for &os;-specific configuration details and the application's website for more general configuration instructions. Mail Host and Mailboxes The mail host is a server that is responsible for delivering and receiving mail for a host or a network. The mail host collects all mail sent to the domain and stores it either in the default mbox or the alternative Maildir format, depending on the configuration. Once mail has been stored, it may either be read locally using a MUA or remotely accessed and collected using protocols such as POP or IMAP. If mail is read locally, a POP or IMAP server does not need to be installed. To access mailboxes remotely, a POP or IMAP server is required as these protocols allow users to connect to their mailboxes from remote locations. IMAP offers several advantages over POP. These include the ability to store a copy of messages on a remote server after they are downloaded and concurrent updates. IMAP can be useful over low-speed links as it allows users to fetch the structure of messages without downloading them. It can also perform tasks such as searching on the server in order to minimize data transfer between clients and servers. Several POP and IMAP servers are available in the Ports Collection. These include mail/qpopper, mail/imap-uw, mail/courier-imap, and mail/dovecot2. It should be noted that both POP and IMAP transmit information, including username and password credentials, in clear-text. To secure the transmission of information across these protocols, consider tunneling sessions over &man.ssh.1; () or using SSL (). Domain Name System (DNS) The Domain Name System (DNS) and its daemon named play a large role in the delivery of email. In order to deliver mail from one site to another, the MTA will look up the remote site in DNS to determine which host will receive mail for the destination. This process also occurs when mail is sent from a remote host to the MTA. In addition to mapping hostnames to IP addresses, DNS is responsible for storing information specific to mail delivery, known as Mail eXchanger MX records. The MX record specifies which hosts will receive mail for a particular domain. To view the MX records for a domain, specify the type of record. Refer to &man.host.1;, for more details about this command: &prompt.user; host -t mx FreeBSD.org FreeBSD.org mail is handled by 10 mx1.FreeBSD.org Refer to for more information about DNS and its configuration. <application>Sendmail</application> Configuration Files ChristopherShumwayContributed by Sendmail Sendmail is the default MTA installed with &os;. It accepts mail from MUAs and delivers it to the appropriate mail host, as defined by its configuration. Sendmail can also accept network connections and deliver mail to local mailboxes or to another program. The configuration files for Sendmail are located in /etc/mail. This section describes these files in more detail. /etc/mail/access /etc/mail/aliases /etc/mail/local-host-names /etc/mail/mailer.conf /etc/mail/mailertable /etc/mail/sendmail.cf /etc/mail/virtusertable /etc/mail/access This access database file defines which hosts or IP addresses have access to the local mail server and what kind of access they have. Hosts listed as , which is the default option, are allowed to send mail to this host as long as the mail's final destination is the local machine. Hosts listed as are rejected for all mail connections. Hosts listed as are allowed to send mail for any destination using this mail server. Hosts listed as will have their mail returned with the specified mail error. If a host is listed as , Sendmail will abort the current search for this entry without accepting or rejecting the mail. Hosts listed as will have their messages held and will receive the specified text as the reason for the hold. Examples of using these options for both IPv4 and IPv6 addresses can be found in the &os; sample configuration, /etc/mail/access.sample: # $FreeBSD$ # # Mail relay access control list. Default is to reject mail unless the # destination is local, or listed in /etc/mail/local-host-names # ## Examples (commented out for safety) #From:cyberspammer.com ERROR:"550 We don't accept mail from spammers" #From:okay.cyberspammer.com OK #Connect:sendmail.org RELAY #To:sendmail.org RELAY #Connect:128.32 RELAY #Connect:128.32.2 SKIP #Connect:IPv6:1:2:3:4:5:6:7 RELAY #Connect:suspicious.example.com QUARANTINE:Mail from suspicious host #Connect:[127.0.0.3] OK #Connect:[IPv6:1:2:3:4:5:6:7:8] OK To configure the access database, use the format shown in the sample to make entries in /etc/mail/access, but do not put a comment symbol (#) in front of the entries. Create an entry for each host or network whose access should be configured. Mail senders that match the left side of the table are affected by the action on the right side of the table. Whenever this file is updated, update its database and restart Sendmail: &prompt.root; makemap hash /etc/mail/access < /etc/mail/access &prompt.root; service sendmail restart /etc/mail/aliases This database file contains a list of virtual mailboxes that are expanded to users, files, programs, or other aliases. Here are a few entries to illustrate the file format: root: localuser ftp-bugs: joe,eric,paul bit.bucket: /dev/null procmail: "|/usr/local/bin/procmail" The mailbox name on the left side of the colon is expanded to the target(s) on the right. The first entry expands the root mailbox to the localuser mailbox, which is then looked up in the /etc/mail/aliases database. If no match is found, the message is delivered to localuser. The second entry shows a mail list. Mail to ftp-bugs is expanded to the three local mailboxes joe, eric, and paul. A remote mailbox could be specified as user@example.com. The third entry shows how to write mail to a file, in this case /dev/null. The last entry demonstrates how to send mail to a program, /usr/local/bin/procmail, through a &unix; pipe. Refer to &man.aliases.5; for more information about the format of this file. Whenever this file is updated, run newaliases to update and initialize the aliases database. /etc/mail/sendmail.cf This is the master configuration file for Sendmail. It controls the overall behavior of Sendmail, including everything from rewriting email addresses to printing rejection messages to remote mail servers. Accordingly, this configuration file is quite complex. Fortunately, this file rarely needs to be changed for standard mail servers. The master Sendmail configuration file can be built from &man.m4.1; macros that define the features and behavior of Sendmail. Refer to /usr/src/contrib/sendmail/cf/README for some of the details. Whenever changes to this file are made, Sendmail needs to be restarted for the changes to take effect. /etc/mail/virtusertable This database file maps mail addresses for virtual domains and users to real mailboxes. These mailboxes can be local, remote, aliases defined in /etc/mail/aliases, or files. This allows multiple virtual domains to be hosted on one machine. &os; provides a sample configuration file in /etc/mail/virtusertable.sample to further demonstrate its format. The following example demonstrates how to create custom entries using that format: root@example.com root postmaster@example.com postmaster@noc.example.net @example.com joe This file is processed in a first match order. When an email address matches the address on the left, it is mapped to the local mailbox listed on the right. The format of the first entry in this example maps a specific email address to a local mailbox, whereas the format of the second entry maps a specific email address to a remote mailbox. Finally, any email address from example.com which has not matched any of the previous entries will match the last mapping and be sent to the local mailbox joe. When creating custom entries, use this format and add them to /etc/mail/virtusertable. Whenever this file is edited, update its database and restart Sendmail: &prompt.root; makemap hash /etc/mail/virtusertable < /etc/mail/virtusertable &prompt.root; service sendmail restart /etc/mail/relay-domains In a default &os; installation, Sendmail is configured to only send mail from the host it is running on. For example, if a POP server is available, users will be able to check mail from remote locations but they will not be able to send outgoing emails from outside locations. Typically, a few moments after the attempt, an email will be sent from MAILER-DAEMON with a 5.7 Relaying Denied message. The most straightforward solution is to add the ISP's FQDN to /etc/mail/relay-domains. If multiple addresses are needed, add them one per line: your.isp.example.com other.isp.example.net users-isp.example.org www.example.org After creating or editing this file, restart Sendmail with service sendmail restart. Now any mail sent through the system by any host in this list, provided the user has an account on the system, will succeed. This allows users to send mail from the system remotely without opening the system up to relaying SPAM from the Internet. Changing the Mail Transfer Agent AndrewBoothmanWritten by GregoryNeil ShapiroInformation taken from emails written by email change mta &os; comes with Sendmail already installed as the MTA which is in charge of outgoing and incoming mail. However, the system administrator can change the system's MTA. A wide choice of alternative MTAs is available from the mail category of the &os; Ports Collection. Once a new MTA is installed, configure and test the new software before replacing Sendmail. Refer to the documentation of the new MTA for information on how to configure the software. Once the new MTA is working, use the instructions in this section to disable Sendmail and configure &os; to use the replacement MTA. Disable <application>Sendmail</application> If Sendmail's outgoing mail service is disabled, it is important that it is replaced with an alternative mail delivery system. Otherwise, system functions such as &man.periodic.8; will be unable to deliver their results by email. Many parts of the system expect a functional MTA. If applications continue to use Sendmail's binaries to try to send email after they are disabled, mail could go into an inactive Sendmail queue and never be delivered. In order to completely disable Sendmail, add or edit the following lines in /etc/rc.conf: sendmail_enable="NO" sendmail_submit_enable="NO" sendmail_outbound_enable="NO" sendmail_msp_queue_enable="NO" To only disable Sendmail's incoming mail service, use only this entry in /etc/rc.conf: sendmail_enable="NO" More information on Sendmail's startup options is available in &man.rc.sendmail.8;. Replace the Default <acronym>MTA</acronym> When a new MTA is installed using the Ports Collection, its startup script is also installed and startup instructions are mentioned in its package message. Before starting the new MTA, stop the running Sendmail processes. This example stops all of these services, then starts the Postfix service: &prompt.root; service sendmail stop &prompt.root; service postfix start To start the replacement MTA at system boot, add its configuration line to /etc/rc.conf. This entry enables the Postfix MTA: postfix_enable="YES" Some extra configuration is needed as Sendmail is so ubiquitous that some software assumes it is already installed and configured. Check /etc/periodic.conf and make sure that these values are set to NO. If this file does not exist, create it with these entries: daily_clean_hoststat_enable="NO" daily_status_mail_rejects_enable="NO" daily_status_include_submit_mailq="NO" daily_submit_queuerun="NO" Some alternative MTAs provide their own compatible implementations of the Sendmail command-line interface in order to facilitate using them as drop-in replacements for Sendmail. However, some MUAs may try to execute standard Sendmail binaries instead of the new MTA's binaries. &os; uses /etc/mail/mailer.conf to map the expected Sendmail binaries to the location of the new binaries. More information about this mapping can be found in &man.mailwrapper.8;. The default /etc/mail/mailer.conf looks like this: # $FreeBSD$ # # Execute the "real" sendmail program, named /usr/libexec/sendmail/sendmail # sendmail /usr/libexec/sendmail/sendmail send-mail /usr/libexec/sendmail/sendmail mailq /usr/libexec/sendmail/sendmail newaliases /usr/libexec/sendmail/sendmail hoststat /usr/libexec/sendmail/sendmail purgestat /usr/libexec/sendmail/sendmail When any of the commands listed on the left are run, the system actually executes the associated command shown on the right. This system makes it easy to change what binaries are executed when these default binaries are invoked. Some MTAs, when installed using the Ports Collection, will prompt to update this file for the new binaries. For example, Postfix will update the file like this: # # Execute the Postfix sendmail program, named /usr/local/sbin/sendmail # sendmail /usr/local/sbin/sendmail send-mail /usr/local/sbin/sendmail mailq /usr/local/sbin/sendmail newaliases /usr/local/sbin/sendmail If the installation of the MTA does not automatically update /etc/mail/mailer.conf, edit this file in a text editor so that it points to the new binaries. This example points to the binaries installed by mail/ssmtp: sendmail /usr/local/sbin/ssmtp send-mail /usr/local/sbin/ssmtp mailq /usr/libexec/sendmail/sendmail newaliases /usr/libexec/sendmail/sendmail hoststat /usr/libexec/sendmail/sendmail purgestat /usr/libexec/sendmail/sendmail Once everything is configured, it is recommended to reboot the system. Rebooting provides the opportunity to ensure that the system is correctly configured to start the new MTA automatically on boot. Troubleshooting email troubleshooting Why do I have to use the FQDN for hosts on my site? The host may actually be in a different domain. For example, in order for a host in foo.bar.edu to reach a host called mumble in the bar.edu domain, refer to it by the Fully-Qualified Domain Name FQDN, mumble.bar.edu, instead of just mumble. This is because the version of BIND BIND which ships with &os; no longer provides default abbreviations for non-FQDNs other than the local domain. An unqualified host such as mumble must either be found as mumble.foo.bar.edu, or it will be searched for in the root domain. In older versions of BIND, the search continued across mumble.bar.edu, and mumble.edu. RFC 1535 details why this is considered bad practice or even a security hole. As a good workaround, place the line: search foo.bar.edu bar.edu instead of the previous: domain foo.bar.edu into /etc/resolv.conf. However, make sure that the search order does not go beyond the boundary between local and public administration, as RFC 1535 calls it. How can I run a mail server on a dial-up PPP host? Connect to a &os; mail gateway on the LAN. The PPP connection is non-dedicated. One way to do this is to get a full-time Internet server to provide secondary MX MX record services for the domain. In this example, the domain is example.com and the ISP has configured example.net to provide secondary MX services to the domain: example.com. MX 10 example.com. MX 20 example.net. Only one host should be specified as the final recipient. For Sendmail, add Cw example.com in /etc/mail/sendmail.cf on example.com. When the sending MTA attempts to deliver mail, it will try to connect to the system, example.com, over the PPP link. This will time out if the destination is offline. The MTA will automatically deliver it to the secondary MX site at the Internet Service Provider (ISP), example.net. The secondary MX site will periodically try to connect to the primary MX host, example.com. Use something like this as a login script: #!/bin/sh # Put me in /usr/local/bin/pppmyisp ( sleep 60 ; /usr/sbin/sendmail -q ) & /usr/sbin/ppp -direct pppmyisp When creating a separate login script for users, instead use sendmail -qRexample.com in the script above. This will force all mail in the queue for example.com to be processed immediately. A further refinement of the situation can be seen from this example from the &a.isp;: > we provide the secondary MX for a customer. The customer connects to > our services several times a day automatically to get the mails to > his primary MX (We do not call his site when a mail for his domains > arrived). Our sendmail sends the mailqueue every 30 minutes. At the > moment he has to stay 30 minutes online to be sure that all mail is > gone to the primary MX. > > Is there a command that would initiate sendmail to send all the mails > now? The user has not root-privileges on our machine of course. In the privacy flags section of sendmail.cf, there is a definition Opgoaway,restrictqrun Remove restrictqrun to allow non-root users to start the queue processing. You might also like to rearrange the MXs. We are the 1st MX for our customers like this, and we have defined: # If we are the best MX for a host, try directly instead of generating # local config error. OwTrue That way a remote site will deliver straight to you, without trying the customer connection. You then send to your customer. Only works for hosts, so you need to get your customer to name their mail machine customer.com as well as hostname.customer.com in the DNS. Just put an A record in the DNS for customer.com. Advanced Topics This section covers more involved topics such as mail configuration and setting up mail for an entire domain. Basic Configuration email configuration Out of the box, one can send email to external hosts as long as /etc/resolv.conf is configured or the network has access to a configured DNS server. To have email delivered to the MTA on the &os; host, do one of the following: Run a DNS server for the domain. Get mail delivered directly to to the FQDN for the machine. SMTP In order to have mail delivered directly to a host, it must have a permanent static IP address, not a dynamic IP address. If the system is behind a firewall, it must be configured to allow SMTP traffic. To receive mail directly at a host, one of these two must be configured: Make sure that the lowest-numbered MXMX record record in DNS points to the host's static IP address. Make sure there is no MX entry in the DNS for the host. Either of the above will allow mail to be received directly at the host. Try this: &prompt.root; hostname example.FreeBSD.org &prompt.root; host example.FreeBSD.org example.FreeBSD.org has address 204.216.27.XX In this example, mail sent directly to yourlogin@example.FreeBSD.org should work without problems, assuming Sendmail is running correctly on example.FreeBSD.org. For this example: &prompt.root; host example.FreeBSD.org example.FreeBSD.org has address 204.216.27.XX example.FreeBSD.org mail is handled (pri=10) by hub.FreeBSD.org All mail sent to example.FreeBSD.org will be collected on hub under the same username instead of being sent directly to your host. The above information is handled by the DNS server. The DNS record that carries mail routing information is the MX entry. If no MX record exists, mail will be delivered directly to the host by way of its IP address. The MX entry for freefall.FreeBSD.org at one time looked like this: freefall MX 30 mail.crl.net freefall MX 40 agora.rdrop.com freefall MX 10 freefall.FreeBSD.org freefall MX 20 who.cdrom.com freefall had many MX entries. The lowest MX number is the host that receives mail directly, if available. If it is not accessible for some reason, the next lower-numbered host will accept messages temporarily, and pass it along when a lower-numbered host becomes available. Alternate MX sites should have separate Internet connections in order to be most useful. Your ISP can provide this service. Mail for a Domain When configuring a MTA for a network, any mail sent to hosts in its domain should be diverted to the MTA so that users can receive their mail on the master mail server. DNS To make life easiest, a user account with the same username should exist on both the MTA and the system with the MUA. Use &man.adduser.8; to create the user accounts. The MTA must be the designated mail exchanger for each workstation on the network. This is done in theDNS configuration with an MX record: example.FreeBSD.org A 204.216.27.XX ; Workstation MX 10 hub.FreeBSD.org ; Mailhost This will redirect mail for the workstation to the MTA no matter where the A record points. The mail is sent to the MX host. This must be configured on a DNS server. If the network does not run its own DNS server, talk to the ISP or DNS provider. The following is an example of virtual email hosting. Consider a customer with the domain customer1.org, where all the mail for customer1.org should be sent to mail.myhost.com. The DNS entry should look like this: customer1.org MX 10 mail.myhost.com An A> record is not needed for customer1.org in order to only handle email for that domain. However, running ping against customer1.org will not work unless an A record exists for it. Tell the MTA which domains and/or hostnames it should accept mail for. Either of the following will work for Sendmail: Add the hosts to /etc/mail/local-host-names when using the FEATURE(use_cw_file). For versions of Sendmail earlier than 8.10, edit /etc/sendmail.cw instead. Add a Cwyour.host.com line to /etc/sendmail.cf. For Sendmail 8.10 or higher, add that line to /etc/mail/sendmail.cf. Setting Up to Send Only BillMoranContributed by There are many instances where one may only want to send mail through a relay. Some examples are: The computer is a desktop machine that needs to use programs such as &man.send-pr.1;, using the ISP's mail relay. The computer is a server that does not handle mail locally, but needs to pass off all mail to a relay for processing. While any MTA is capable of filling this particular niche, it can be difficult to properly configure a full-featured MTA just to handle offloading mail. Programs such as Sendmail and Postfix are overkill for this use. Additionally, a typical Internet access service agreement may forbid one from running a mail server. The easiest way to fulfill those needs is to install the mail/ssmtp port: &prompt.root; cd /usr/ports/mail/ssmtp &prompt.root; make install replace clean Once installed, mail/ssmtp can be configured with /usr/local/etc/ssmtp/ssmtp.conf: root=yourrealemail@example.com mailhub=mail.example.com rewriteDomain=example.com hostname=_HOSTNAME_ Use the real email address for root. Enter the ISP's outgoing mail relay in place of mail.example.com. Some ISPs call this the outgoing mail server or SMTP server). Make sure to disable Sendmail, including the outgoing mail service. See for details. mail/ssmtp has some other options available. Refer to the examples in /usr/local/etc/ssmtp or the manual page of ssmtp for more information. Setting up ssmtp in this manner allows any software on the computer that needs to send mail to function properly, while not violating the ISP's usage policy or allowing the computer to be hijacked for spamming. Using Mail with a Dialup Connection When using a static IP address, one should not need to adjust the default configuration. Set the hostname to the assigned Internet name and Sendmail will do the rest. When using a dynamically assigned IP address and a dialup PPP connection to the Internet, one usually has a mailbox on the ISP's mail server. In this example, the ISP's domain is example.net, the user name is user, the hostname is bsd.home, and the ISP has allowed relay.example.net as a mail relay. In order to retrieve mail from the ISP's mailbox, install a retrieval agent from the Ports Collection. mail/fetchmail is a good choice as it supports many different protocols. Usually, the ISP will provide POP. When using user PPP, email can be automatically fetched when an Internet connection is established with the following entry in /etc/ppp/ppp.linkup: MYADDR: !bg su user -c fetchmail When using Sendmail to deliver mail to non-local accounts, configure Sendmail to process the mail queue as soon as the Internet connection is established. To do this, add this line after the above fetchmail entry in /etc/ppp/ppp.linkup: !bg su user -c "sendmail -q" In this example, there is an account for user on bsd.home. In the home directory of user on bsd.home, create a .fetchmailrc which contains this line: poll example.net protocol pop3 fetchall pass MySecret This file should not be readable by anyone except user as it contains the password MySecret. In order to send mail with the correct from: header, configure Sendmail to use user@example.net rather than user@bsd.home and to send all mail via relay.example.net, allowing quicker mail transmission. The following .mc file should suffice: VERSIONID(`bsd.home.mc version 1.0') OSTYPE(bsd4.4)dnl FEATURE(nouucp)dnl MAILER(local)dnl MAILER(smtp)dnl Cwlocalhost Cwbsd.home MASQUERADE_AS(`example.net')dnl FEATURE(allmasquerade)dnl FEATURE(masquerade_envelope)dnl FEATURE(nocanonify)dnl FEATURE(nodns)dnl define(`SMART_HOST', `relay.example.net') Dmbsd.home define(`confDOMAIN_NAME',`bsd.home')dnl define(`confDELIVERY_MODE',`deferred')dnl Refer to the previous section for details of how to convert this file into the sendmail.cf format. Do not forget to restart Sendmail after updating sendmail.cf. SMTP Authentication JamesGorhamWritten by Configuring SMTP authentication on the MTA provides a number of benefits. SMTP authentication adds a layer of security to Sendmail, and provides mobile users who switch hosts the ability to use the same MTA without the need to reconfigure their mail client's settings each time. Install security/cyrus-sasl2 from the Ports Collection. This port supports a number of compile-time options. For the SMTP authentication method demonstrated in this example, make sure that is not disabled. After installing security/cyrus-sasl2, edit /usr/local/lib/sasl2/Sendmail.conf, or create it if it does not exist, and add the following line: pwcheck_method: saslauthd Next, install security/cyrus-sasl2-saslauthd and add the following line to /etc/rc.conf: saslauthd_enable="YES" Finally, start the saslauthd daemon: &prompt.root; service saslauthd start This daemon serves as a broker for sendmail to authenticate against the &os; &man.passwd.5; database. This saves the trouble of creating a new set of usernames and passwords for each user that needs to use SMTP authentication, and keeps the login and mail password the same. Next, edit /etc/make.conf and add the following lines: SENDMAIL_CFLAGS=-I/usr/local/include/sasl -DSASL SENDMAIL_LDFLAGS=-L/usr/local/lib SENDMAIL_LDADD=-lsasl2 These lines provide Sendmail the proper configuration options for linking to cyrus-sasl2 at compile time. Make sure that cyrus-sasl2 has been installed before recompiling Sendmail. Recompile Sendmail by executing the following commands: &prompt.root; cd /usr/src/lib/libsmutil &prompt.root; make cleandir && make obj && make &prompt.root; cd /usr/src/lib/libsm &prompt.root; make cleandir && make obj && make &prompt.root; cd /usr/src/usr.sbin/sendmail &prompt.root; make cleandir && make obj && make && make install This compile should not have any problems if /usr/src has not changed extensively and the shared libraries it needs are available. After Sendmail has been compiled and reinstalled, edit /etc/mail/freebsd.mc or the local .mc file. Many administrators choose to use the output from &man.hostname.1; as the name of the .mc file for uniqueness. Add these lines: dnl set SASL options TRUST_AUTH_MECH(`GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl define(`confAUTH_MECHANISMS', `GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl These options configure the different methods available to Sendmail for authenticating users. To use a method other than pwcheck, refer to the Sendmail documentation. Finally, run &man.make.1; while in /etc/mail. That will run the new .mc and create a .cf named either freebsd.cf or the name used for the local .mc. Then, run make install restart, which will copy the file to sendmail.cf, and properly restart Sendmail. For more information about this process, refer to /etc/mail/Makefile. To test the configuration, use a MUA to send a test message. For further investigation, set the of Sendmail to 13 and watch /var/log/maillog for any errors. For more information, refer to SMTP authentication. Mail User Agents MarcSilverContributed by Mail User Agents A MUA is an application that is used to send and receive email. As email evolves and becomes more complex, MUAs are becoming increasingly powerful and provide users increased functionality and flexibility. The mail category of the &os; Ports Collection contains numerous MUAs. These include graphical email clients such as Evolution or Balsa and console based clients such as mutt or alpine. <command>mail</command> &man.mail.1; is the default MUA installed with &os;. It is a console based MUA that offers the basic functionality required to send and receive text-based email. It provides limited attachment support and can only access local mailboxes. Although mail does not natively support interaction with POP or IMAP servers, these mailboxes may be downloaded to a local mbox using an application such as fetchmail. In order to send and receive email, run mail: &prompt.user; mail The contents of the user's mailbox in /var/mail are automatically read by mail. Should the mailbox be empty, the utility exits with a message indicating that no mail could be found. If mail exists, the application interface starts, and a list of messages will be displayed. Messages are automatically numbered, as can be seen in the following example: Mail version 8.1 6/6/93. Type ? for help. "/var/mail/marcs": 3 messages 3 new >N 1 root@localhost Mon Mar 8 14:05 14/510 "test" N 2 root@localhost Mon Mar 8 14:05 14/509 "user account" N 3 root@localhost Mon Mar 8 14:05 14/509 "sample" Messages can now be read by typing t followed by the message number. This example reads the first email: & t 1 Message 1: From root@localhost Mon Mar 8 14:05:52 2004 X-Original-To: marcs@localhost Delivered-To: marcs@localhost To: marcs@localhost Subject: test Date: Mon, 8 Mar 2004 14:05:52 +0200 (SAST) From: root@localhost (Charlie Root) This is a test message, please reply if you receive it. As seen in this example, the message will be displayed with full headers. To display the list of messages again, press h. If the email requires a reply, press either R or r mail keys. R instructs mail to reply only to the sender of the email, while r replies to all other recipients of the message. These commands can be suffixed with the mail number of the message to reply to. After typing the response, the end of the message should be marked by a single . on its own line. An example can be seen below: & R 1 To: root@localhost Subject: Re: test Thank you, I did get your email. . EOT In order to send a new email, press m, followed by the recipient email address. Multiple recipients may be specified by separating each address with the , delimiter. The subject of the message may then be entered, followed by the message contents. The end of the message should be specified by putting a single . on its own line. & mail root@localhost Subject: I mastered mail Now I can send and receive email using mail ... :) . EOT While using mail, press ? to display help at any time. Refer to &man.mail.1; for more help on how to use mail. &man.mail.1; was not designed to handle attachments and thus deals with them poorly. Newer MUAs handle attachments in a more intelligent way. Users who prefer to use mail may find the converters/mpack port to be of considerable use. <application>mutt</application> mutt is a powerful MUA, with many features, including: The ability to thread messages. PGP support for digital signing and encryption of email. MIME support. Maildir support. Highly customizable. Refer to http://www.mutt.org for more information on mutt. mutt may be installed using the mail/mutt port. After the port has been installed, mutt can be started by issuing the following command: &prompt.user; mutt mutt will automatically read and display the contents of the user mailbox in /var/mail. If no mails are found, mutt will wait for commands from the user. The example below shows mutt displaying a list of messages: To read an email, select it using the cursor keys and press Enter. An example of mutt displaying email can be seen below: Similar to &man.mail.1;, mutt can be used to reply only to the sender of the message as well as to all recipients. To reply only to the sender of the email, press r. To send a group reply to the original sender as well as all the message recipients, press g. By default, mutt uses the &man.vi.1; editor for creating and replying to emails. Each user can customize this by creating or editing the .muttrc in their home directory and setting the editor variable or by setting the EDITOR environment variable. Refer to http://www.mutt.org/ for more information about configuring mutt. To compose a new mail message, press m. After a valid subject has been given, mutt will start &man.vi.1; so the email can be written. Once the contents of the email are complete, save and quit from vi. mutt will resume, displaying a summary screen of the mail that is to be delivered. In order to send the mail, press y. An example of the summary screen can be seen below: mutt contains extensive help which can be accessed from most of the menus by pressing ?. The top line also displays the keyboard shortcuts where appropriate. <application>alpine</application> alpine is aimed at a beginner user, but also includes some advanced features. alpine has had several remote vulnerabilities discovered in the past, which allowed remote attackers to execute arbitrary code as users on the local system, by the action of sending a specially-prepared email. While known problems have been fixed, alpine code is written in an insecure style and the &os; Security Officer believes there are likely to be other undiscovered vulnerabilities. Users install alpine at their own risk. The current version of alpine may be installed using the mail/alpine port. Once the port has installed, alpine can be started by issuing the following command: &prompt.user; alpine The first time alpine runs, it displays a greeting page with a brief introduction, as well as a request from the alpine development team to send an anonymous email message allowing them to judge how many users are using their client. To send this anonymous message, press Enter. Alternatively, press E to exit the greeting without sending an anonymous message. An example of the greeting page is shown below: The main menu is then presented, which can be navigated using the cursor keys. This main menu provides shortcuts for the composing new mails, browsing mail directories, and administering address book entries. Below the main menu, relevant keyboard shortcuts to perform functions specific to the task at hand are shown. The default directory opened by alpine is inbox. To view the message index, press I, or select the MESSAGE INDEX option shown below: The message index shows messages in the current directory and can be navigated by using the cursor keys. Highlighted messages can be read by pressing Enter. In the screenshot below, a sample message is displayed by alpine. Contextual keyboard shortcuts are displayed at the bottom of the screen. An example of one of a shortcut is r, which tells the MUA to reply to the current message being displayed. Replying to an email in alpine is done using the pico editor, which is installed by default with alpine. pico makes it easy to navigate the message and is easier for novice users to use than &man.vi.1; or &man.mail.1;. Once the reply is complete, the message can be sent by pressing CtrlX . alpine will ask for confirmation before sending the message. alpine can be customized using the SETUP option from the main menu. Consult http://www.washington.edu/alpine/ for more information. Using <application>fetchmail</application> MarcSilverContributed by fetchmail fetchmail is a full-featured IMAP and POP client. It allows users to automatically download mail from remote IMAP and POP servers and save it into local mailboxes where it can be accessed more easily. fetchmail can be installed using the mail/fetchmail port, and offers various features, including: Support for the POP3, APOP, KPOP, IMAP, ETRN and ODMR protocols. Ability to forward mail using SMTP, which allows filtering, forwarding, and aliasing to function normally. May be run in daemon mode to check periodically for new messages. Can retrieve multiple mailboxes and forward them, based on configuration, to different local users. This section explains some of the basic features of fetchmail. This utility requires a .fetchmailrc configuration in the user's home directory in order to run correctly. This file includes server information as well as login credentials. Due to the sensitive nature of the contents of this file, it is advisable to make it readable only by the user, with the following command: &prompt.user; chmod 600 .fetchmailrc The following .fetchmailrc serves as an example for downloading a single user mailbox using POP. It tells fetchmail to connect to example.com using a username of joesoap and a password of XXX. This example assumes that the user joesoap exists on the local system. poll example.com protocol pop3 username "joesoap" password "XXX" The next example connects to multiple POP and IMAP servers and redirects to different local usernames where applicable: poll example.com proto pop3: user "joesoap", with password "XXX", is "jsoap" here; user "andrea", with password "XXXX"; poll example2.net proto imap: user "john", with password "XXXXX", is "myth" here; fetchmail can be run in daemon mode by running it with , followed by the interval (in seconds) that fetchmail should poll servers listed in .fetchmailrc. The following example configures fetchmail to poll every 600 seconds: &prompt.user; fetchmail -d 600 More information on fetchmail can be found at http://www.fetchmail.info/. Using <application>procmail</application> MarcSilverContributed by procmail procmail is a powerful application used to filter incoming mail. It allows users to define rules which can be matched to incoming mails to perform specific functions or to reroute mail to alternative mailboxes or email addresses. procmail can be installed using the mail/procmail port. Once installed, it can be directly integrated into most MTAs. Consult the MTA documentation for more information. Alternatively, procmail can be integrated by adding the following line to a .forward in the home directory of the user: "|exec /usr/local/bin/procmail || exit 75" The following section displays some basic procmail rules, as well as brief descriptions of what they do. Rules must be inserted into a .procmailrc, which must reside in the user's home directory. The majority of these rules can be found in &man.procmailex.5;. To forward all mail from user@example.com to an external address of goodmail@example2.com: :0 * ^From.*user@example.com ! goodmail@example2.com To forward all mails shorter than 1000 bytes to an external address of goodmail@example2.com: :0 * < 1000 ! goodmail@example2.com To send all mail sent to alternate@example.com to a mailbox called alternate: :0 * ^TOalternate@example.com alternate To send all mail with a subject of Spam to /dev/null: :0 ^Subject:.*Spam /dev/null A useful recipe that parses incoming &os;.org mailing lists and places each list in its own mailbox: :0 * ^Sender:.owner-freebsd-\/[^@]+@FreeBSD.ORG { LISTNAME=${MATCH} :0 * LISTNAME??^\/[^@]+ FreeBSD-${MATCH} } Index: head/en_US.ISO8859-1/books/handbook/mirrors/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/mirrors/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/mirrors/chapter.xml (revision 46052) @@ -1,933 +1,934 @@ Obtaining &os; + xml:id="mirrors"> + Obtaining &os; <acronym>CD</acronym> and <acronym>DVD</acronym> Sets &os; CD and DVD sets are available from several online retailers:
&os; Mall, Inc. 2420 Sand Creek Rd C-1 #347 Brentwood, CA 94513 USA Phone: +1 925 240-6652 Fax: +1 925 674-0821 Email: info@freebsdmall.com WWW: http://www.freebsdmall.com/
Getlinux 78 Rue de la Croix Rochopt Épinay-sous-Sénart 91860 France Email: contact@getlinux.fr WWW: http://www.getlinux.fr/
Dr. Hinner EDV Kochelseestr. 11 D-81371 München Germany Phone: (0177) 428 419 0 Email: infow@hinner.de WWW: http://www.hinner.de/linux/freebsd.html
Linux Center Galernaya Street, 55 Saint-Petersburg 190000 Russia Phone: +7-812-309-06-86 Email: info@linuxcenter.ru WWW: http://linuxcenter.ru/shop/freebsd
<acronym>FTP</acronym> Sites The official sources for &os; are available via anonymous FTP from a worldwide set of mirror sites. The site ftp://ftp.FreeBSD.org/pub/FreeBSD/ is well connected and allows a large number of connections to it, but you are probably better off finding a closer mirror site (especially if you decide to set up some sort of mirror site). Additionally, &os; is available via anonymous FTP from the following mirror sites. If you choose to obtain &os; via anonymous FTP, please try to use a site near you. The mirror sites listed as Primary Mirror Sites typically have the entire &os; archive (all the currently available versions for each of the architectures) but you will probably have faster download times from a site that is in your country or region. The regional sites carry the most recent versions for the most popular architecture(s) but might not carry the entire &os; archive. All sites provide access via anonymous FTP but some sites also provide access via other methods. The access methods available for each site are provided in parentheses after the hostname. &chap.mirrors.ftp.index.inc; &chap.mirrors.lastmod.inc; &chap.mirrors.ftp.inc; Using CTM CTM CTM is a method for keeping a remote directory tree in sync with a central one. It is built into &os; and can be used to synchronize a system with &os;'s source repositories. It supports synchronization of an entire repository or just a specified set of branches. CTM is specifically designed for use on lousy or non-existent TCP/IP connections and provides the ability for changes to be automatically sent by email. It requires the user to obtain up to three deltas per day for the most active branches. Update sizes are always kept as small as possible and are typically less than 5K. About one in very ten updates is 10-50K in size, and there will occasionally be an update larger than 100K+. When using CTM to track &os; development, refer to the caveats related to working directly from the development sources rather than a pre-packaged release. These are discussed in Tracking a Development Branch. Little documentation exists on the process of creating deltas or using CTM for other purposes. Contact the &a.ctm-users.name; mailing list for answers to questions on using CTM. Getting Deltas The deltas used by CTM can be obtained either through anonymous FTP or email. FTP deltas can be obtained from the following mirror sites. When using anonymous FTP to obtain CTM deltas, select a mirror that is geographically nearby. In case of problems, contact the &a.ctm-users.name; mailing list. California, Bay Area, official source ftp://ftp.FreeBSD.org/pub/FreeBSD/development/CTM/ ftp://ftp.FreeBSD.org/pub/FreeBSD/CTM/ South Africa, backup server for old deltas ftp://ftp.za.FreeBSD.org/pub/FreeBSD/CTM/ Taiwan/R.O.C. ftp://ctm.tw.FreeBSD.org/pub/FreeBSD/development/CTM/ ftp://ctm2.tw.FreeBSD.org/pub/FreeBSD/development/CTM/ ftp://ctm3.tw.FreeBSD.org/pub/FreeBSD/development/CTM/ To instead receive deltas through email, subscribe to one of the ctm-src distribution lists available from http://lists.freebsd.org/mailman/listinfo. For example, &a.ctm-src-cur.name; supports the head development branch and &a.ctm-src-9.name; supports the 9.X release branch. As CTM updates arrive through email, use ctm_rmail to unpack and apply them. This command can be run directly from an entry in /etc/aliases in order to automate this process. Refer to &man.ctm.rmail.1; for more details. Regardless of the method which is used to get deltas, CTM users should subscribe to the &a.ctm-announce.name; mailing list as this is the only mechanism by which CTM announcements are posted. <application>CTM</application> Usage Before CTM deltas can be used for the first time, a starting point must be produced. One method is to apply a starter delta to an empty directory. A starter delta can be recognized by the XEmpty in its name, such as src-cur.3210XEmpty.gz. The designation following the X corresponds to the origin of the initial seed, where Empty is an empty directory. As a rule, a base transition from Empty is produced every 100 deltas. Be aware that starter deltas are large and 70 to 80 Megabytes of gzip'd data is common for the XEmpty deltas. Another method is to copy or extract an initial source from a RELEASE media as this can save a significant transfer of data from the Internet. Once a base delta has been created, apply all deltas with higher numbers. To apply the deltas: &prompt.root; cd /directory/to/store/the/stuff &prompt.root; ctm -v -v /directory/which/stores/the/deltas/src-xxx.* Multiple deltas can be applied with a single command as they will be processed one at a time and any deltas that are already applied will be ignored. CTM understands gzip compressed deltas, which saves disk space. To verify a delta without applying it, include in the command line. CTM will not actually modify the local tree but will instead verify the integrity of the delta to see if it would apply cleanly. Refer to &man.ctm.1; for more information about available options and an overview of the process CTM uses when applying deltas. To keep the local source tree up-to-date, every time a new delta becomes available, apply it through CTM. Once applied, it is recommended to not delete the deltas if it is a burden to download them again. This way, a local copy is available in case it is needed for future disaster recovery. Keeping Local Changes Developers often experiment with and change files in their local source tree. CTM supports local modifications in a limited way: before checking for the presence of a file, it first looks for a file with the same name and a .ctm extension. If this file exists, CTM will operate on it instead of the original filename. This behavior provides a simple way to maintain local changes. Before modifying a file, make a copy with a .ctm suffix. Make any changes to the original filename, knowing that CTM will only apply updates to the file with the .ctm suffix. Other <application>CTM</application> Options Finding Out Exactly What Would Be Touched by an Update To determine the list of changes that CTM will make to the local source repository, use . This option is useful for creating logs of the changes or when performing pre- or post-processing on any of the modified files. Making Backups Before Updating To backup all of the files that would be changed by a CTM update, specify . This option tells CTM to backup all files touched by the applied CTM delta to backup-file. Restricting the Files Touched by an Update To restrict the scope of a given CTM update, or to extract just a few files from a sequence of deltas, filtering regular expressions can be specified using , which specifies which files to process, or , which specifies which files to ignore. For example, to extract an up-to-date copy of lib/libc/Makefile from a collection of saved CTM deltas: &prompt.root; cd /directory/to/extract/to/ &prompt.root; ctm -e '^lib/libc/Makefile' /directory/which/stores/the/deltas/src-xxx.* For every file specified in a CTM delta, and are applied in the order given on the command line. A file is processed by CTM only if it is marked as eligible after all and options are applied. Using <application>Subversion</application> Subversion Introduction As of July 2012, &os; uses Subversion as the primary version control system for storing all of &os;'s source code, documentation, and the Ports Collection. Subversion is generally a developer tool. Most users should use freebsd-update () to update the &os; base system, and portsnap () to update the &os; Ports Collection. This chapter demonstrates how to install Subversion on a &os; system and then use it to create a local copy of a &os; repository. It includes a list of the available &os; Subversion mirrors and resources to additional information on how to use Subversion. Installation Subversion must be installed before it can be used to check out the contents of any of the repositories. If a copy of the ports tree is already present, one can install Subversion like this: &prompt.root; cd /usr/ports/devel/subversion &prompt.root; make install clean If the ports tree is not available, Subversion can be installed as a package: &prompt.root; pkg install devel/subversion Running <application>Subversion</application> The svn command is used to fetch a clean copy of the sources into a local directory. The files in this directory are called a local working copy. Move or delete the local directory before using checkout. Checkout over an existing non-svn directory can cause conflicts between the existing files and those brought in from the repository. Subversion uses URLs to designate a repository, taking the form of protocol://hostname/path. Mirrors may support different protocols as specified below. The first component of the path is the &os; repository to access. There are three different repositories, base for the &os; base system source code, ports for the Ports Collection, and doc for documentation. For example, the URL svn://svn0.us-east.FreeBSD.org/ports/head/ specifies the main branch of the ports repository on the svn0.us-east.FreeBSD.org mirror, using the svn protocol. A checkout from a given repository is performed with a command like this: &prompt.root; svn checkout svn-mirror/repository/branch lwcdir where: svn-mirror is a URL for one of the Subversion mirror sites. repository is one of the Project repositories, i.e., base, ports, or doc. branch depends on the repository used. ports and doc are mostly updated in the head branch, while base maintains the latest version of -CURRENT under head and the respective latest versions of the -STABLE branches under stable/8 (for 8.x), stable/9 (9.x) and stable/10 (10.x). lwcdir is the target directory where the contents of the specified branch should be placed. This is usually /usr/ports for ports, /usr/src for base, and /usr/doc for doc. This example checks out the Ports Collection from the western US repository using the HTTPS protocol, placing the local working copy in /usr/ports. If /usr/ports is already present but was not created by svn, remember to rename or delete it before the checkout. &prompt.root; svn checkout https://svn0.us-west.FreeBSD.org/ports/head /usr/ports Because the initial checkout has to download the full branch of the remote repository, it can take a while. Please be patient. After the initial checkout, the local working copy can be updated by running: &prompt.root; svn update lwcdir To update /usr/ports created in the example above, use: &prompt.root; svn update /usr/ports The update is much quicker than a checkout, only transferring files that have changed. An alternate way of updating the local working copy after checkout is provided by the Makefile in the /usr/ports, /usr/src, and /usr/doc directories. Set SVN_UPDATE and use the update target. For example, to update /usr/src: &prompt.root; cd /usr/src &prompt.root; make update SVN_UPDATE=yes <application>Subversion</application> Mirror Sites Subversion Repository Mirror Sites All mirrors carry all repositories. The master &os; Subversion server, svn.FreeBSD.org, is publicly accessible, read-only. That may change in the future, so users are encouraged to use one of the official mirrors. To view the &os; Subversion repositories through a browser, use http://svnweb.FreeBSD.org/. The &os; Subversion mirror network is still in its early days, and will likely change. Do not count on this list of mirrors being static. In particular, the SSL certificates of the servers will likely change at some point. Name Protocols Location SSL Fingerprint svn0.us-west.FreeBSD.org svn, http, https USA, California SHA1 1C:BD:85:95:11:9F:EB:75:A5:4B:C8:A3:FE:08:E4:02:73:06:1E:61 svn0.us-east.FreeBSD.org svn, http, https, rsync USA, New Jersey SHA1 1C:BD:85:95:11:9F:EB:75:A5:4B:C8:A3:FE:08:E4:02:73:06:1E:61 svn0.eu.FreeBSD.org svn, http, https, rsync Europe, UK SHA1 39:B0:53:35:CE:60:C7:BB:00:54:96:96:71:10:94:BB:CE:1C:07:A7 svn0.ru.FreeBSD.org svn, http, https, rsync Russia, Moscow SHA1 F6:44:AA:B9:03:89:0E:3E:8C:4D:4D:14:F0:27:E6:C7:C1:8B:17:C5 HTTPS is the preferred protocol, providing protection against another computer pretending to be the &os; mirror (commonly known as a man in the middle attack) or otherwise trying to send bad content to the end user. On the first connection to an HTTPS mirror, the user will be asked to verify the server fingerprint: Error validating server certificate for 'https://svn0.us-west.freebsd.org:443': - The certificate is not issued by a trusted authority. Use the fingerprint to validate the certificate manually! - The certificate hostname does not match. Certificate information: - Hostname: svnmir.ysv.FreeBSD.org - Valid: from Jul 29 22:01:21 2013 GMT until Dec 13 22:01:21 2040 GMT - Issuer: clusteradm, FreeBSD.org, (null), CA, US (clusteradm@FreeBSD.org) - Fingerprint: 1C:BD:85:95:11:9F:EB:75:A5:4B:C8:A3:FE:08:E4:02:73:06:1E:61 (R)eject, accept (t)emporarily or accept (p)ermanently? Compare the fingerprint shown to those listed in the table above. If the fingerprint matches, the server security certificate can be accepted temporarily or permanently. A temporary certificate will expire after a single session with the server, and the verification step will be repeated on the next connection. Accepting the certificate permanently will store the authentication credentials in ~/.subversion/auth/ and the user will not be asked to verify the fingerprint again until the certificate expires. If https cannot be used due to firewall or other problems, svn is the next choice, with slightly faster transfers. When neither can be used, use http. For More Information For other information about using Subversion, please see the Subversion Book, titled Version Control with Subversion, or the Subversion Documentation. Using <application>rsync</application> The following sites make &os; available through the rsync protocol. The rsync utility works in much the same way as the &man.rcp.1; command, but has more options and uses the rsync remote-update protocol which transfers only the differences between two sets of files, thus greatly speeding up the synchronization over the network. This is most useful if you are a mirror site for the &os; FTP server, or the CVS repository. The rsync suite is available for many operating systems, on &os;, see the net/rsync port or use the package. Czech Republic rsync://ftp.cz.FreeBSD.org/ Available collections: ftp: A partial mirror of the &os; FTP server. &os;: A full mirror of the &os; FTP server. Netherlands rsync://ftp.nl.FreeBSD.org/ Available collections: &os;: A full mirror of the &os; FTP server. Russia rsync://ftp.mtu.ru/ Available collections: &os;: A full mirror of the &os; FTP server. &os;-Archive: The mirror of &os; Archive FTP server. Sweden rsync://ftp4.se.freebsd.org/ Available collections: &os;: A full mirror of the &os; FTP server. Taiwan rsync://ftp.tw.FreeBSD.org/ rsync://ftp2.tw.FreeBSD.org/ rsync://ftp6.tw.FreeBSD.org/ Available collections: &os;: A full mirror of the &os; FTP server. United Kingdom rsync://rsync.mirrorservice.org/ Available collections: ftp.freebsd.org: A full mirror of the &os; FTP server. United States of America rsync://ftp-master.FreeBSD.org/ This server may only be used by &os; primary mirror sites. Available collections: &os;: The master archive of the &os; FTP server. acl: The &os; master ACL list. rsync://ftp13.FreeBSD.org/ Available collections: &os;: A full mirror of the &os; FTP server. Index: head/en_US.ISO8859-1/books/handbook/pgpkeys/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/pgpkeys/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/pgpkeys/chapter.xml (revision 46052) @@ -1,38 +1,39 @@ Open<acronym>PGP</acronym> Keys + xml:id="pgpkeys"> + Open<acronym>PGP</acronym> Keys pgp keys The OpenPGP keys of the FreeBSD.org officers are shown here. These keys can be used to verify a signature or send encrypted email to one of the officers. A full list of &os; OpenPGP keys is available in the PGP Keys article. The complete keyring can be downloaded at https://www.FreeBSD.org/doc/pgpkeyring.txt. Officers §ion.pgpkeys-officers; Index: head/en_US.ISO8859-1/books/handbook/preface/preface.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/preface/preface.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/preface/preface.xml (revision 46052) @@ -1,686 +1,687 @@ Preface + xml:id="book-preface"> + Preface Intended Audience The &os; newcomer will find that the first section of this book guides the user through the &os; installation process and gently introduces the concepts and conventions that underpin &unix;. Working through this section requires little more than the desire to explore, and the ability to take on board new concepts as they are introduced. Once you have traveled this far, the second, far larger, section of the Handbook is a comprehensive reference to all manner of topics of interest to &os; system administrators. Some of these chapters may recommend that you do some prior reading, and this is noted in the synopsis at the beginning of each chapter. For a list of additional sources of information, please see . Changes from the Third Edition The current online version of the Handbook represents the cumulative effort of many hundreds of contributors over the past 10 years. The following are some of the significant changes since the two volume third edition was published in 2004: has been added with information about the powerful &dtrace; performance analysis tool. has been added with information about non-native file systems in &os;, such as ZFS from &sun;. has been added to cover the new auditing capabilities in &os; and explain its use. has been added with information about installing &os; on virtualization software. has been added to cover installation of &os; using the new installation utility, bsdinstall. Changes from the Second Edition (2004) The third edition was the culmination of over two years of work by the dedicated members of the &os; Documentation Project. The printed edition grew to such a size that it was necessary to publish as two separate volumes. The following are the major changes in this new edition: has been expanded with new information about the ACPI power and resource management, the cron system utility, and more kernel tuning options. has been expanded with new information about virtual private networks (VPNs), file system access control lists (ACLs), and security advisories. is a new chapter with this edition. It explains what MAC is and how this mechanism can be used to secure a &os; system. has been expanded with new information about USB storage devices, file system snapshots, file system quotas, file and network backed filesystems, and encrypted disk partitions. A troubleshooting section has been added to . has been expanded with new information about using alternative transport agents, SMTP authentication, UUCP, fetchmail, procmail, and other advanced topics. is all new with this edition. This chapter includes information about setting up the Apache HTTP Server, ftpd, and setting up a server for µsoft; &windows; clients with Samba. Some sections from were moved here to improve the presentation. has been expanded with new information about using &bluetooth; devices with &os;, setting up wireless networks, and Asynchronous Transfer Mode (ATM) networking. A glossary has been added to provide a central location for the definitions of technical terms used throughout the book. A number of aesthetic improvements have been made to the tables and figures throughout the book. Changes from the First Edition (2001) The second edition was the culmination of over two years of work by the dedicated members of the &os; Documentation Project. The following were the major changes in this edition: A complete Index has been added. All ASCII figures have been replaced by graphical diagrams. A standard synopsis has been added to each chapter to give a quick summary of what information the chapter contains, and what the reader is expected to know. The content has been logically reorganized into three parts: Getting Started, System Administration, and Appendices. was completely rewritten with many screenshots to make it much easier for new users to grasp the text. has been expanded to contain additional information about processes, daemons, and signals. has been expanded to contain additional information about binary package management. has been completely rewritten with an emphasis on using modern desktop technologies such as KDE and GNOME on &xfree86; 4.X. has been expanded. has been written from what used to be two separate chapters on Disks and Backups. We feel that the topics are easier to comprehend when presented as a single chapter. A section on RAID (both hardware and software) has also been added. has been completely reorganized and updated for &os; 4.X/5.X. has been substantially updated. Many new sections have been added to . has been expanded to include more information about configuring sendmail. has been expanded to include information about installing &oracle; and &sap.r3;. The following new topics are covered in this second edition: . . Organization of This Book This book is split into five logically distinct sections. The first section, Getting Started, covers the installation and basic usage of &os;. It is expected that the reader will follow these chapters in sequence, possibly skipping chapters covering familiar topics. The second section, Common Tasks, covers some frequently used features of &os;. This section, and all subsequent sections, can be read out of order. Each chapter begins with a succinct synopsis that describes what the chapter covers and what the reader is expected to already know. This is meant to allow the casual reader to skip around to find chapters of interest. The third section, System Administration, covers administration topics. The fourth section, Network Communication, covers networking and server topics. The fifth section contains appendices of reference information. Introduces &os; to a new user. It describes the history of the &os; Project, its goals and development model. Walks a user through the entire installation process of &os; 9.x and later using bsdinstall. Walks a user through the entire installation process of &os; 8.x and earlier using sysinstall. Some advanced installation topics, such as installing through a serial console, are also covered. Covers the basic commands and functionality of the &os; operating system. If you are familiar with &linux; or another flavor of &unix; then you can probably skip this chapter. Covers the installation of third-party software with both &os;'s innovative Ports Collection and standard binary packages. Describes the X Window System in general and using X11 on &os; in particular. Also describes common desktop environments such as KDE and GNOME. Lists some common desktop applications, such as web browsers and productivity suites, and describes how to install them on &os;. Shows how to set up sound and video playback support for your system. Also describes some sample audio and video applications. Explains why you might need to configure a new kernel and provides detailed instructions for configuring, building, and installing a custom kernel. Describes managing printers on &os;, including information about banner pages, printer accounting, and initial setup. Describes the &linux; compatibility features of &os;. Also provides detailed installation instructions for many popular &linux; applications such as &oracle; and &mathematica;. Describes the parameters available for system administrators to tune a &os; system for optimum performance. Also describes the various configuration files used in &os; and where to find them. Describes the &os; boot process and explains how to control this process with configuration options. Describes many different tools available to help keep your &os; system secure, including Kerberos, IPsec and OpenSSH. Describes the jails framework, and the improvements of jails over the traditional chroot support of &os;. Explains what Mandatory Access Control (MAC) is and how this mechanism can be used to secure a &os; system. Describes what &os; Event Auditing is, how it can be installed, configured, and how audit trails can be inspected or monitored. Describes how to manage storage media and filesystems with &os;. This includes physical disks, RAID arrays, optical and tape media, memory-backed disks, and network filesystems. Describes what the GEOM framework in &os; is and how to configure various supported RAID levels. Examines support of non-native file systems in &os;, like the Z File System from &sun;. Describes what virtualization systems offer, and how they can be used with &os;. Describes how to use &os; in languages other than English. Covers both system and application level localization. Explains the differences between &os;-STABLE, &os;-CURRENT, and &os; releases. Describes which users would benefit from tracking a development system and outlines that process. Covers the methods users may take to update their system to the latest security release. Describes how to configure and use the &dtrace; tool from &sun; in &os;. Dynamic tracing can help locate performance issues, by performing real time system analysis. Explains how to connect terminals and modems to your &os; system for both dial in and dial out connections. Describes how to use PPP to connect to remote systems with &os;. Explains the different components of an email server and dives into simple configuration topics for the most popular mail server software: sendmail. Provides detailed instructions and example configuration files to set up your &os; machine as a network filesystem server, domain name server, network information system server, or time synchronization server. Explains the philosophy behind software-based firewalls and provides detailed information about the configuration of the different firewalls available for &os;. Describes many networking topics, including sharing an Internet connection with other computers on your LAN, advanced routing topics, wireless networking, &bluetooth;, ATM, IPv6, and much more. Lists different sources for obtaining &os; media on CDROM or DVD as well as different sites on the Internet that allow you to download and install &os;. This book touches on many different subjects that may leave you hungry for a more detailed explanation. The bibliography lists many excellent books that are referenced in the text. Describes the many forums available for &os; users to post questions and engage in technical conversations about &os;. Lists the PGP fingerprints of several &os; Developers. Conventions used in this book To provide a consistent and easy to read text, several conventions are followed throughout the book. Typographic Conventions Italic An italic font is used for filenames, URLs, emphasized text, and the first usage of technical terms. Monospace A monospaced font is used for error messages, commands, environment variables, names of ports, hostnames, user names, group names, device names, variables, and code fragments. Bold A bold font is used for applications, commands, and keys. User Input Keys are shown in bold to stand out from other text. Key combinations that are meant to be typed simultaneously are shown with `+' between the keys, such as: Ctrl Alt Del Meaning the user should type the Ctrl, Alt, and Del keys at the same time. Keys that are meant to be typed in sequence will be separated with commas, for example: Ctrl X , Ctrl S Would mean that the user is expected to type the Ctrl and X keys simultaneously and then to type the Ctrl and S keys simultaneously. Examples Examples starting with C:\> indicate a &ms-dos; command. Unless otherwise noted, these commands may be executed from a Command Prompt window in a modern µsoft.windows; environment. E:\> tools\fdimage floppies\kern.flp A: Examples starting with &prompt.root; indicate a command that must be invoked as the superuser in &os;. You can login as root to type the command, or login as your normal account and use &man.su.1; to gain superuser privileges. &prompt.root; dd if=kern.flp of=/dev/fd0 Examples starting with &prompt.user; indicate a command that should be invoked from a normal user account. Unless otherwise noted, C-shell syntax is used for setting environment variables and other shell commands. &prompt.user; top Acknowledgments The book you are holding represents the efforts of many hundreds of people around the world. Whether they sent in fixes for typos, or submitted complete chapters, all the contributions have been useful. Several companies have supported the development of this document by paying authors to work on it full-time, paying for publication, etc. In particular, BSDi (subsequently acquired by Wind River Systems) paid members of the &os; Documentation Project to work on improving this book full time leading up to the publication of the first printed edition in March 2000 (ISBN 1-57176-241-8). Wind River Systems then paid several additional authors to make a number of improvements to the print-output infrastructure and to add additional chapters to the text. This work culminated in the publication of the second printed edition in November 2001 (ISBN 1-57176-303-1). In 2003-2004, &os; Mall, Inc, paid several contributors to improve the Handbook in preparation for the third printed edition. Index: head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml =================================================================== --- head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml (revision 46051) +++ head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml (revision 46052) @@ -1,2200 +1,2199 @@ - Serial Communications Synopsis serial communications &unix; has always had support for serial communications as the very first &unix; machines relied on serial lines for user input and output. Things have changed a lot from the days when the average terminal consisted of a 10-character-per-second serial printer and a keyboard. This chapter covers some of the ways serial communications can be used on &os;. After reading this chapter, you will know: How to connect terminals to a &os; system. How to use a modem to dial out to remote hosts. How to allow remote users to login to a &os; system with a modem. How to boot a &os; system from a serial console. Before reading this chapter, you should: Know how to configure and install a custom kernel. Understand &os; permissions and processes. Have access to the technical manual for the serial hardware to be used with &os;. Serial Terminology and Hardware The following terms are often used in serial communications: bps Bits per Secondbits-per-second (bps) is the rate at which data is transmitted. DTE Data Terminal EquipmentDTE (DTE) is one of two endpoints in a serial communication. An example would be a computer. DCE Data Communications EquipmentDCE (DTE) is the other endpoint in a serial communication. Typically, it is a modem or serial terminal. RS-232 The original standard which defined hardware serial communications. It has since been renamed to TIA-232. When referring to communication data rates, this section does not use the term baud. Baud refers to the number of electrical state transitions made in a period of time, while bps is the correct term to use. To connect a serial terminal to a &os; system, a serial port on the computer and the proper cable to connect to the serial device are needed. Users who are already familiar with serial hardware and cabling can safely skip this section. Serial Cables and Ports There are several different kinds of serial cables. The two most common types are null-modem cables and standard RS-232 cables. The documentation for the hardware should describe the type of cable required. These two types of cables differ in how the wires are connected to the connector. Each wire represents a signal, with the defined signals summarized in . A standard serial cable passes all of the RS-232C signals straight through. For example, the Transmitted Data pin on one end of the cable goes to the Transmitted Data pin on the other end. This is the type of cable used to connect a modem to the &os; system, and is also appropriate for some terminals. A null-modem cable switches the Transmitted Data pin of the connector on one end with the Received Data pin on the other end. The connector can be either a DB-25 or a DB-9. A null-modem cable can be constructed using the pin connections summarized in , , and . While the standard calls for a straight-through pin 1 to pin 1 Protective Ground line, it is often omitted. Some terminals work using only pins 2, 3, and 7, while others require different configurations. When in doubt, refer to the documentation for the hardware. null-modem cable <acronym>RS-232C</acronym> Signal Names Acronyms Names RD Received Data TD Transmitted Data DTR Data Terminal Ready DSR Data Set Ready DCD Data Carrier Detect SG Signal Ground RTS Request to Send CTS Clear to Send
DB-25 to DB-25 Null-Modem Cable Signal Pin # Pin # Signal SG 7 connects to 7 SG TD 2 connects to 3 RD RD 3 connects to 2 TD RTS 4 connects to 5 CTS CTS 5 connects to 4 RTS DTR 20 connects to 6 DSR DTR 20 connects to 8 DCD DSR 6 connects to 20 DTR DCD 8 connects to 20 DTR
DB-9 to DB-9 Null-Modem Cable Signal Pin # Pin # Signal RD 2 connects to 3 TD TD 3 connects to 2 RD DTR 4 connects to 6 DSR DTR 4 connects to 1 DCD SG 5 connects to 5 SG DSR 6 connects to 4 DTR DCD 1 connects to 4 DTR RTS 7 connects to 8 CTS CTS 8 connects to 7 RTS
DB-9 to DB-25 Null-Modem Cable Signal Pin # Pin # Signal RD 2 connects to 2 TD TD 3 connects to 3 RD DTR 4 connects to 6 DSR DTR 4 connects to 8 DCD SG 5 connects to 7 SG DSR 6 connects to 20 DTR DCD 1 connects to 20 DTR RTS 7 connects to 5 CTS CTS 8 connects to 4 RTS
When one pin at one end connects to a pair of pins at the other end, it is usually implemented with one short wire between the pair of pins in their connector and a long wire to the other single pin. Serial ports are the devices through which data is transferred between the &os; host computer and the terminal. Several kinds of serial ports exist. Before purchasing or constructing a cable, make sure it will fit the ports on the terminal and on the &os; system. Most terminals have DB-25 ports. Personal computers may have DB-25 or DB-9 ports. A multiport serial card may have RJ-12 or RJ-45/ ports. See the documentation that accompanied the hardware for specifications on the kind of port or visually verify the type of port. In &os;, each serial port is accessed through an entry in /dev. There are two different kinds of entries: Call-in ports are named /dev/ttyuN where N is the port number, starting from zero. If a terminal is connected to the first serial port (COM1), use /dev/ttyu0 to refer to the terminal. If the terminal is on the second serial port (COM2), use /dev/ttyu1, and so forth. Generally, the call-in port is used for terminals. Call-in ports require that the serial line assert the Data Carrier Detect signal to work correctly. Call-out ports are named /dev/cuauN on &os; versions 10.x and higher and /dev/cuadN on &os; versions 9.x and lower. Call-out ports are usually not used for terminals, but are used for modems. The call-out port can be used if the serial cable or the terminal does not support the Data Carrier Detect signal. &os; also provides initialization devices (/dev/ttyuN.init and /dev/cuauN.init or /dev/cuadN.init) and locking devices (/dev/ttyuN.lock and /dev/cuauN.lock or /dev/cuadN.lock). The initialization devices are used to initialize communications port parameters each time a port is opened, such as crtscts for modems which use RTS/CTS signaling for flow control. The locking devices are used to lock flags on ports to prevent users or programs changing certain parameters. Refer to &man.termios.4;, &man.sio.4;, and &man.stty.1; for information on terminal settings, locking and initializing devices, and setting terminal options, respectively. Serial Port Configuration By default, &os; supports four serial ports which are commonly known as COM1, COM2, COM3, and COM4. &os; also supports dumb multi-port serial interface cards, such as the BocaBoard 1008 and 2016, as well as more intelligent multi-port cards such as those made by Digiboard. However, the default kernel only looks for the standard COM ports. To see if the system recognizes the serial ports, look for system boot messages that start with uart: &prompt.root; grep uart /var/run/dmesg.boot If the system does not recognize all of the needed serial ports, additional entries can be added to /boot/device.hints. This file already contains hint.uart.0.* entries for COM1 and hint.uart.1.* entries for COM2. When adding a port entry for COM3 use 0x3E8, and for COM4 use 0x2E8. Common IRQ addresses are 5 for COM3 and 9 for COM4. ttyu cuau To determine the default set of terminal I/O settings used by the port, specify its device name. This example determines the settings for the call-in port on COM2: &prompt.root; stty -a -f /dev/ttyu1 System-wide initialization of serial devices is controlled by /etc/rc.d/serial. This file affects the default settings of serial devices. To change the settings for a device, use stty. By default, the changed settings are in effect until the device is closed and when the device is reopened, it goes back to the default set. To permanently change the default set, open and adjust the settings of the initialization device. For example, to turn on mode, 8 bit communication, and flow control for ttyu5, type: &prompt.root; stty -f /dev/ttyu5.init clocal cs8 ixon ixoff rc files rc.serial To prevent certain settings from being changed by an application, make adjustments to the locking device. For example, to lock the speed of ttyu5 to 57600 bps, type: &prompt.root; stty -f /dev/ttyu5.lock 57600 Now, any application that opens ttyu5 and tries to change the speed of the port will be stuck with 57600 bps. Terminals Sean Kelly Contributed by terminals Terminals provide a convenient and low-cost way to access a &os; system when not at the computer's console or on a connected network. This section describes how to use terminals with &os;. The original &unix; systems did not have consoles. Instead, users logged in and ran programs through terminals that were connected to the computer's serial ports. The ability to establish a login session on a serial port still exists in nearly every &unix;-like operating system today, including &os;. By using a terminal attached to an unused serial port, a user can log in and run any text program that can normally be run on the console or in an xterm window. Many terminals can be attached to a &os; system. An older spare computer can be used as a terminal wired into a more powerful computer running &os;. This can turn what might otherwise be a single-user computer into a powerful multiple-user system. &os; supports three types of terminals: Dumb terminals Dumb terminals are specialized hardware that connect to computers over serial lines. They are called dumb because they have only enough computational power to display, send, and receive text. No programs can be run on these devices. Instead, dumb terminals connect to a computer that runs the needed programs. There are hundreds of kinds of dumb terminals made by many manufacturers, and just about any kind will work with &os;. Some high-end terminals can even display graphics, but only certain software packages can take advantage of these advanced features. Dumb terminals are popular in work environments where workers do not need access to graphical applications. Computers Acting as Terminals Since a dumb terminal has just enough ability to display, send, and receive text, any spare computer can be a dumb terminal. All that is needed is the proper cable and some terminal emulation software to run on the computer. This configuration can be useful. For example, if one user is busy working at the &os; system's console, another user can do some text-only work at the same time from a less powerful personal computer hooked up as a terminal to the &os; system. There are at least two utilities in the base-system of &os; that can be used to work through a serial connection: &man.cu.1; and &man.tip.1;. For example, to connect from a client system that runs &os; to the serial connection of another system: &prompt.root; cu -l serial-port-device Replace serial-port-device with the device name of the connected serial port. These device files are called /dev/cuauN on &os; versions 10.x and higher and /dev/cuadN on &os; versions 9.x and lower. In either case, N is the serial port number, starting from zero. This means that COM1 is /dev/cuau0 or /dev/cuad0 in &os;. Additional programs are available through the Ports Collection, such as comms/minicom. X Terminals X terminals are the most sophisticated kind of terminal available. Instead of connecting to a serial port, they usually connect to a network like Ethernet. Instead of being relegated to text-only applications, they can display any &xorg; application. This chapter does not cover the setup, configuration, or use of X terminals. Terminal Configuration This section describes how to configure a &os; system to enable a login session on a serial terminal. It assumes that the system recognizes the serial port to which the terminal is connected and that the terminal is connected with the correct cable. In &os;, init reads /etc/ttys and starts a getty process on the available terminals. The getty process is responsible for reading a login name and starting the login program. The ports on the &os; system which allow logins are listed in /etc/ttys. For example, the first virtual console, ttyv0, has an entry in this file, allowing logins on the console. This file also contains entries for the other virtual consoles, serial ports, and pseudo-ttys. For a hardwired terminal, the serial port's /dev entry is listed without the /dev part. For example, /dev/ttyv0 is listed as ttyv0. The default /etc/ttys configures support for the first four serial ports, ttyu0 through ttyu3: ttyu0 "/usr/libexec/getty std.9600" dialup off secure ttyu1 "/usr/libexec/getty std.9600" dialup off secure ttyu2 "/usr/libexec/getty std.9600" dialup off secure ttyu3 "/usr/libexec/getty std.9600" dialup off secure When attaching a terminal to one of those ports, modify the default entry to set the required speed and terminal type, to turn the device on and, if needed, to change the port's secure setting. If the terminal is connected to another port, add an entry for the port. configures two terminals in /etc/ttys. The first entry configures a Wyse-50 connected to COM2. The second entry configures an old computer running Procomm terminal software emulating a VT-100 terminal. The computer is connected to the sixth serial port on a multi-port serial card. Configuring Terminal Entries ttyu1 "/usr/libexec/getty std.38400" wy50 on insecure ttyu5 "/usr/libexec/getty std.19200" vt100 on insecure The first field specifies the device name of the serial terminal. The second field tells getty to initialize and open the line, set the line speed, prompt for a user name, and then execute the login program. The optional getty type configures characteristics on the terminal line, like bps rate and parity. The available getty types are listed in /etc/gettytab. In almost all cases, the getty types that start with std will work for hardwired terminals as these entries ignore parity. There is a std entry for each bps rate from 110 to 115200. Refer to &man.gettytab.5; for more information. When setting the getty type, make sure to match the communications settings used by the terminal. For this example, the Wyse-50 uses no parity and connects at 38400 bps. The computer uses no parity and connects at 19200 bps. The third field is the type of terminal. For dial-up ports, unknown or dialup is typically used since users may dial up with practically any type of terminal or software. Since the terminal type does not change for hardwired terminals, a real terminal type from /etc/termcap can be specified. For this example, the Wyse-50 uses the real terminal type while the computer running Procomm is set to emulate a VT-100. The fourth field specifies if the port should be enabled. To enable logins on this port, this field must be set to on. The final field is used to specify whether the port is secure. Marking a port as secure means that it is trusted enough to allow root to login from that port. Insecure ports do not allow root logins. On an insecure port, users must login from unprivileged accounts and then use su or a similar mechanism to gain superuser privileges, as described in . For security reasons, it is recommended to change this setting to insecure. After making any changes to /etc/ttys, send a SIGHUP (hangup) signal to the init process to force it to re-read its configuration file: &prompt.root; kill -HUP 1 Since init is always the first process run on a system, it always has a process ID of 1. If everything is set up correctly, all cables are in place, and the terminals are powered up, a getty process should now be running on each terminal and login prompts should be available on each terminal. Troubleshooting the Connection Even with the most meticulous attention to detail, something could still go wrong while setting up a terminal. Here is a list of common symptoms and some suggested fixes. If no login prompt appears, make sure the terminal is plugged in and powered up. If it is a personal computer acting as a terminal, make sure it is running terminal emulation software on the correct serial port. Make sure the cable is connected firmly to both the terminal and the &os; computer. Make sure it is the right kind of cable. Make sure the terminal and &os; agree on the bps rate and parity settings. For a video display terminal, make sure the contrast and brightness controls are turned up. If it is a printing terminal, make sure paper and ink are in good supply. Use ps to make sure that a getty process is running and serving the terminal. For example, the following listing shows that a getty is running on the second serial port, ttyu1, and is using the std.38400 entry in /etc/gettytab: &prompt.root; ps -axww|grep ttyu 22189 d1 Is+ 0:00.03 /usr/libexec/getty std.38400 ttyu1 If no getty process is running, make sure the port is enabled in /etc/ttys. Remember to run kill -HUP 1 after modifying /etc/ttys. If the getty process is running but the terminal still does not display a login prompt, or if it displays a prompt but will not accept typed input, the terminal or cable may not support hardware handshaking. Try changing the entry in /etc/ttys from std.38400 to 3wire.38400, then run kill -HUP 1 after modifying /etc/ttys. The 3wire entry is similar to std, but ignores hardware handshaking. The baud rate may need to be reduced or software flow control enabled when using 3wire to prevent buffer overflows. If garbage appears instead of a login prompt, make sure the terminal and &os; agree on the bps rate and parity settings. Check the getty processes to make sure the correct getty type is in use. If not, edit /etc/ttys and run kill -HUP 1. If characters appear doubled and the password appears when typed, switch the terminal, or the terminal emulation software, from half duplex or local echo to full duplex. Dial-in Service Guy Helmer Contributed by Sean Kelly Additions by dial-in service Configuring a &os; system for dial-in service is similar to configuring terminals, except that modems are used instead of terminal devices. &os; supports both external and internal modems. External modems are more convenient because they often can be configured via parameters stored in non-volatile RAM and they usually provide lighted indicators that display the state of important RS-232 signals, indicating whether the modem is operating properly. Internal modems usually lack non-volatile RAM, so their configuration may be limited to setting DIP switches. If the internal modem has any signal indicator lights, they are difficult to view when the system's cover is in place. modem When using an external modem, a proper cable is needed. A standard RS-232C serial cable should suffice. &os; needs the RTS and CTS signals for flow control at speeds above 2400 bps, the CD signal to detect when a call has been answered or the line has been hung up, and the DTR signal to reset the modem after a session is complete. Some cables are wired without all of the needed signals, so if a login session does not go away when the line hangs up, there may be a problem with the cable. Refer to for more information about these signals. Like other &unix;-like operating systems, &os; uses the hardware signals to find out when a call has been answered or a line has been hung up and to hangup and reset the modem after a call. &os; avoids sending commands to the modem or watching for status reports from the modem. &os; supports the NS8250, NS16450, NS16550, and NS16550A-based RS-232C (CCITT V.24) communications interfaces. The 8250 and 16450 devices have single-character buffers. The 16550 device provides a 16-character buffer, which allows for better system performance. Bugs in plain 16550 devices prevent the use of the 16-character buffer, so use 16550A devices if possible. Because single-character-buffer devices require more work by the operating system than the 16-character-buffer devices, 16550A-based serial interface cards are preferred. If the system has many active serial ports or will have a heavy load, 16550A-based cards are better for low-error-rate communications. The rest of this section demonstrates how to configure a modem to receive incoming connections, how to communicate with the modem, and offers some troubleshooting tips. Modem Configuration getty As with terminals, init spawns a getty process for each configured serial port used for dial-in connections. When a user dials the modem's line and the modems connect, the Carrier Detect signal is reported by the modem. The kernel notices that the carrier has been detected and instructs getty to open the port and display a login: prompt at the specified initial line speed. In a typical configuration, if garbage characters are received, usually due to the modem's connection speed being different than the configured speed, getty tries adjusting the line speeds until it receives reasonable characters. After the user enters their login name, getty executes login, which completes the login process by asking for the user's password and then starting the user's shell. /usr/bin/login There are two schools of thought regarding dial-up modems. One confiuration method is to set the modems and systems so that no matter at what speed a remote user dials in, the dial-in RS-232 interface runs at a locked speed. The benefit of this configuration is that the remote user always sees a system login prompt immediately. The downside is that the system does not know what a user's true data rate is, so full-screen programs like Emacs will not adjust their screen-painting methods to make their response better for slower connections. The second method is to configure the RS-232 interface to vary its speed based on the remote user's connection speed. Because getty does not understand any particular modem's connection speed reporting, it gives a login: message at an initial speed and watches the characters that come back in response. If the user sees junk, they should press Enter until they see a recognizable prompt. If the data rates do not match, getty sees anything the user types as junk, tries the next speed, and gives the login: prompt again. This procedure normally only takes a keystroke or two before the user sees a good prompt. This login sequence does not look as clean as the locked-speed method, but a user on a low-speed connection should receive better interactive response from full-screen programs. When locking a modem's data communications rate at a particular speed, no changes to /etc/gettytab should be needed. However, for a matching-speed configuration, additional entries may be required in order to define the speeds to use for the modem. This example configures a 14.4 Kbps modem with a top interface speed of 19.2 Kbps using 8-bit, no parity connections. It configures getty to start the communications rate for a V.32bis connection at 19.2 Kbps, then cycles through 9600 bps, 2400 bps, 1200 bps, 300 bps, and back to 19.2 Kbps. Communications rate cycling is implemented with the nx= (next table) capability. Each line uses a tc= (table continuation) entry to pick up the rest of the settings for a particular data rate. # # Additions for a V.32bis Modem # um|V300|High Speed Modem at 300,8-bit:\ :nx=V19200:tc=std.300: un|V1200|High Speed Modem at 1200,8-bit:\ :nx=V300:tc=std.1200: uo|V2400|High Speed Modem at 2400,8-bit:\ :nx=V1200:tc=std.2400: up|V9600|High Speed Modem at 9600,8-bit:\ :nx=V2400:tc=std.9600: uq|V19200|High Speed Modem at 19200,8-bit:\ :nx=V9600:tc=std.19200: For a 28.8 Kbps modem, or to take advantage of compression on a 14.4 Kbps modem, use a higher communications rate, as seen in this example: # # Additions for a V.32bis or V.34 Modem # Starting at 57.6 Kbps # vm|VH300|Very High Speed Modem at 300,8-bit:\ :nx=VH57600:tc=std.300: vn|VH1200|Very High Speed Modem at 1200,8-bit:\ :nx=VH300:tc=std.1200: vo|VH2400|Very High Speed Modem at 2400,8-bit:\ :nx=VH1200:tc=std.2400: vp|VH9600|Very High Speed Modem at 9600,8-bit:\ :nx=VH2400:tc=std.9600: vq|VH57600|Very High Speed Modem at 57600,8-bit:\ :nx=VH9600:tc=std.57600: For a slow CPU or a heavily loaded system without 16550A-based serial ports, this configuration may produce sio silo errors at 57.6 Kbps. /etc/ttys The configuration of /etc/ttys is similar to , but a different argument is passed to getty and dialup is used for the terminal type. Replace xxx with the process init will run on the device: ttyu0 "/usr/libexec/getty xxx" dialup on The dialup terminal type can be changed. For example, setting vt102 as the default terminal type allows users to use VT102 emulation on their remote systems. For a locked-speed configuration, specify the speed with a valid type listed in /etc/gettytab. This example is for a modem whose port speed is locked at 19.2 Kbps: ttyu0 "/usr/libexec/getty std.19200" dialup on In a matching-speed configuration, the entry needs to reference the appropriate beginning auto-baud entry in /etc/gettytab. To continue the example for a matching-speed modem that starts at 19.2 Kbps, use this entry: ttyu0 "/usr/libexec/getty V19200" dialup on After editing /etc/ttys, wait until the modem is properly configured and connected before signaling init: &prompt.root; kill -HUP 1 rc files rc.serial High-speed modems, like V.32, V.32bis, and V.34 modems, use hardware (RTS/CTS) flow control. Use stty to set the hardware flow control flag for the modem port. This example sets the crtscts flag on COM2's dial-in and dial-out initialization devices: &prompt.root; stty -f /dev/ttyu1.init crtscts &prompt.root; stty -f /dev/cuau1.init crtscts Troubleshooting This section provides a few tips for troubleshooting a dial-up modem that will not connect to a &os; system. Hook up the modem to the &os; system and boot the system. If the modem has status indication lights, watch to see whether the modem's DTR indicator lights when the login: prompt appears on the system's console. If it lights up, that should mean that &os; has started a getty process on the appropriate communications port and is waiting for the modem to accept a call. If the DTR indicator does not light, login to the &os; system through the console and type ps ax to see if &os; is running a getty process on the correct port: 114 ?? I 0:00.10 /usr/libexec/getty V19200 ttyu0 If the second column contains a d0 instead of a ?? and the modem has not accepted a call yet, this means that getty has completed its open on the communications port. This could indicate a problem with the cabling or a misconfigured modem because getty should not be able to open the communications port until the carrier detect signal has been asserted by the modem. If no getty processes are waiting to open the port, double-check that the entry for the port is correct in /etc/ttys. Also, check /var/log/messages to see if there are any log messages from init or getty. Next, try dialing into the system. Be sure to use 8 bits, no parity, and 1 stop bit on the remote system. If a prompt does not appear right away, or the prompt shows garbage, try pressing Enter about once per second. If there is still no login: prompt, try sending a BREAK. When using a high-speed modem, try dialing again after locking the dialing modem's interface speed. If there is still no login: prompt, check /etc/gettytab again and double-check that: The initial capability name specified in the entry in /etc/ttys matches the name of a capability in /etc/gettytab. Each nx= entry matches another gettytab capability name. Each tc= entry matches another gettytab capability name. If the modem on the &os; system will not answer, make sure that the modem is configured to answer the phone when DTR is asserted. If the modem seems to be configured correctly, verify that the DTR line is asserted by checking the modem's indicator lights. If it still does not work, try sending an email to the &a.questions; describing the modem and the problem. Dial-out Service dial-out service The following are tips for getting the host to connect over the modem to another computer. This is appropriate for establishing a terminal session with a remote host. This kind of connection can be helpful to get a file on the Internet if there are problems using PPP. If PPP is not working, use the terminal session to FTP the needed file. Then use zmodem to transfer it to the machine. Using a Stock Hayes Modem A generic Hayes dialer is built into tip. Use at=hayes in /etc/remote. The Hayes driver is not smart enough to recognize some of the advanced features of newer modems messages like BUSY, NO DIALTONE, or CONNECT 115200. Turn those messages off when using tip with ATX0&W. The dial timeout for tip is 60 seconds. The modem should use something less, or else tip will think there is a communication problem. Try ATS7=45&W. Using <literal>AT</literal> Commands /etc/remote Create a direct entry in /etc/remote. For example, if the modem is hooked up to the first serial port, /dev/cuau0, use the following line: cuau0:dv=/dev/cuau0:br#19200:pa=none Use the highest bps rate the modem supports in the br capability. Then, type tip cuau0 to connect to the modem. Or, use cu as root with the following command: &prompt.root; cu -lline -sspeed line is the serial port, such as /dev/cuau0, and speed is the speed, such as 57600. When finished entering the AT commands, type ~. to exit. The <literal>@</literal> Sign Does Not Work The @ sign in the phone number capability tells tip to look in /etc/phones for a phone number. But, the @ sign is also a special character in capability files like /etc/remote, so it needs to be escaped with a backslash: pn=\@ Dialing from the Command Line Put a generic entry in /etc/remote. For example: tip115200|Dial any phone number at 115200 bps:\ :dv=/dev/cuau0:br#115200:at=hayes:pa=none:du: tip57600|Dial any phone number at 57600 bps:\ :dv=/dev/cuau0:br#57600:at=hayes:pa=none:du: This should now work: &prompt.root; tip -115200 5551234 Users who prefer cu over tip, can use a generic cu entry: cu115200|Use cu to dial any number at 115200bps:\ :dv=/dev/cuau1:br#57600:at=hayes:pa=none:du: and type: &prompt.root; cu 5551234 -s 115200 Setting the <acronym>bps</acronym> Rate Put in an entry for tip1200 or cu1200, but go ahead and use whatever bps rate is appropriate with the br capability. tip thinks a good default is 1200 bps which is why it looks for a tip1200 entry. 1200 bps does not have to be used, though. Accessing a Number of Hosts Through a Terminal Server Rather than waiting until connected and typing CONNECT host each time, use tip's cm capability. For example, these entries in /etc/remote will let you type tip pain or tip muffin to connect to the hosts pain or muffin, and tip deep13 to connect to the terminal server. pain|pain.deep13.com|Forrester's machine:\ :cm=CONNECT pain\n:tc=deep13: muffin|muffin.deep13.com|Frank's machine:\ :cm=CONNECT muffin\n:tc=deep13: deep13:Gizmonics Institute terminal server:\ :dv=/dev/cuau2:br#38400:at=hayes:du:pa=none:pn=5551234: Using More Than One Line with <command>tip</command> This is often a problem where a university has several modem lines and several thousand students trying to use them. Make an entry in /etc/remote and use @ for the pn capability: big-university:\ :pn=\@:tc=dialout dialout:\ :dv=/dev/cuau3:br#9600:at=courier:du:pa=none: Then, list the phone numbers in /etc/phones: big-university 5551111 big-university 5551112 big-university 5551113 big-university 5551114 tip will try each number in the listed order, then give up. To keep retrying, run tip in a while loop. Using the Force Character Ctrl P is the default force character, used to tell tip that the next character is literal data. The force character can be set to any other character with the ~s escape, which means set a variable. Type ~sforce=single-char followed by a newline. single-char is any single character. If single-char is left out, then the force character is the null character, which is accessed by typing Ctrl2 or CtrlSpace . A pretty good value for single-char is Shift Ctrl 6 , which is only used on some terminal servers. To change the force character, specify the following in ~/.tiprc: force=single-char Upper Case Characters This happens when Ctrl A is pressed, which is tip's raise character, specially designed for people with broken caps-lock keys. Use ~s to set raisechar to something reasonable. It can be set to be the same as the force character, if neither feature is used. Here is a sample ~/.tiprc for Emacs users who need to type Ctrl 2 and Ctrl A : force=^^ raisechar=^^ The ^^ is ShiftCtrl6 . File Transfers with <command>tip</command> When talking to another &unix;-like operating system, files can be sent and received using ~p (put) and ~t (take). These commands run cat and echo on the remote system to accept and send files. The syntax is: ~p local-file remote-file ~t remote-file local-file There is no error checking, so another protocol, like zmodem, should probably be used. Using <application>zmodem</application> with <command>tip</command>? To receive files, start the sending program on the remote end. Then, type ~C rz to begin receiving them locally. To send files, start the receiving program on the remote end. Then, type ~C sz files to send them to the remote system. Setting Up the Serial Console Kazutaka YOKOTA Contributed by Bill Paul Based on a document by serial console &os; has the ability to boot a system with a dumb terminal on a serial port as a console. This configuration is useful for system administrators who wish to install &os; on machines that have no keyboard or monitor attached, and developers who want to debug the kernel or device drivers. As described in , &os; employs a three stage bootstrap. The first two stages are in the boot block code which is stored at the beginning of the &os; slice on the boot disk. The boot block then loads and runs the boot loader as the third stage code. In order to set up booting from a serial console, the boot block code, the boot loader code, and the kernel need to be configured. Quick Serial Console Configuration This section provides a fast overview of setting up the serial console. This procedure can be used when the dumb terminal is connected to COM1. Configuring a Serial Console on <filename>COM1</filename> Connect the serial cable to COM1 and the controlling terminal. To configure boot messages to display on the serial console, issue the following command as the superuser: &prompt.root; echo 'console="comconsole"' >> /boot/loader.conf Edit /etc/ttys and change off to on and dialup to vt100 for the ttyu0 entry. Otherwise, a password will not be required to connect via the serial console, resulting in a potential security hole. Reboot the system to see if the changes took effect. If a different configuration is required, see the next section for a more in-depth configuration explanation. In-Depth Serial Console Configuration This section provides a more detailed explanation of the steps needed to setup a serial console in &os;. Configuring a Serial Console Prepare a serial cable. null-modem cable Use either a null-modem cable or a standard serial cable and a null-modem adapter. See for a discussion on serial cables. Unplug the keyboard. Many systems probe for the keyboard during the Power-On Self-Test (POST) and will generate an error if the keyboard is not detected. Some machines will refuse to boot until the keyboard is plugged in. If the computer complains about the error, but boots anyway, no further configuration is needed. If the computer refuses to boot without a keyboard attached, configure the BIOS so that it ignores this error. Consult the motherboard's manual for details on how to do this. Try setting the keyboard to Not installed in the BIOS. This setting tells the BIOS not to probe for a keyboard at power-on so it should not complain if the keyboard is absent. If that option is not present in the BIOS, look for an Halt on Error option instead. Setting this to All but Keyboard or to No Errors will have the same effect. If the system has a &ps2; mouse, unplug it as well. &ps2; mice share some hardware with the keyboard and leaving the mouse plugged in can fool the keyboard probe into thinking the keyboard is still there. While most systems will boot without a keyboard, quite a few will not boot without a graphics adapter. Some systems can be configured to boot with no graphics adapter by changing the graphics adapter setting in the BIOS configuration to Not installed. Other systems do not support this option and will refuse to boot if there is no display hardware in the system. With these machines, leave some kind of graphics card plugged in, even if it is just a junky mono board. A monitor does not need to be attached. Plug a dumb terminal, an old computer with a modem program, or the serial port on another &unix; box into the serial port. Add the appropriate hint.sio.* entries to /boot/device.hints for the serial port. Some multi-port cards also require kernel configuration options. Refer to &man.sio.4; for the required options and device hints for each supported serial port. Create boot.config in the root directory of the a partition on the boot drive. This file instructs the boot block code how to boot the system. In order to activate the serial console, one or more of the following options are needed. When using multiple options, include them all on the same line: Toggles between the internal and serial consoles. Use this to switch console devices. For instance, to boot from the internal (video) console, use to direct the boot loader and the kernel to use the serial port as its console device. Alternatively, to boot from the serial port, use to tell the boot loader and the kernel to use the video display as the console instead. Toggles between the single and dual console configurations. In the single configuration, the console will be either the internal console (video display) or the serial port, depending on the state of . In the dual console configuration, both the video display and the serial port will become the console at the same time, regardless of the state of . However, the dual console configuration takes effect only while the boot block is running. Once the boot loader gets control, the console specified by becomes the only console. Makes the boot block probe the keyboard. If no keyboard is found, the and options are automatically set. Due to space constraints in the current version of the boot blocks, is capable of detecting extended keyboards only. Keyboards with less than 101 keys and without F11 and F12 keys may not be detected. Keyboards on some laptops may not be properly found because of this limitation. If this is the case, do not use . Use either to select the console automatically or to activate the serial console. Refer to &man.boot.8; and &man.boot.config.5; for more details. The options, except for , are passed to the boot loader. The boot loader will determine whether the internal video or the serial port should become the console by examining the state of . This means that if is specified but is not specified in /boot.config, the serial port can be used as the console only during the boot block as the boot loader will use the internal video display as the console. Boot the machine. When &os; starts, the boot blocks echo the contents of /boot.config to the console. For example: /boot.config: -P Keyboard: no The second line appears only if is in /boot.config and indicates the presence or absence of the keyboard. These messages go to either the serial or internal console, or both, depending on the option in /boot.config: Options Message goes to none internal console serial console serial and internal consoles serial and internal consoles , keyboard present internal console , keyboard absent serial console After the message, there will be a small pause before the boot blocks continue loading the boot loader and before any further messages are printed to the console. Under normal circumstances, there is no need to interrupt the boot blocks, but one can do so in order to make sure things are set up correctly. Press any key, other than Enter, at the console to interrupt the boot process. The boot blocks will then prompt for further action: >> FreeBSD/i386 BOOT Default: 0:ad(0,a)/boot/loader boot: Verify that the above message appears on either the serial or internal console, or both, according to the options in /boot.config. If the message appears in the correct console, press Enter to continue the boot process. If there is no prompt on the serial terminal, something is wrong with the settings. Enter then Enter or Return to tell the boot block (and then the boot loader and the kernel) to choose the serial port for the console. Once the system is up, go back and check what went wrong. During the third stage of the boot process, one can still switch between the internal console and the serial console by setting appropriate environment variables in the boot loader. See &man.loader.8; for more information. This line in /boot/loader.conf or /boot/loader.conf.local configures the boot loader and the kernel to send their boot messages to the serial console, regardless of the options in /boot.config: console="comconsole" That line should be the first line of /boot/loader.conf so that boot messages are displayed on the serial console as early as possible. If that line does not exist, or if it is set to console="vidconsole", the boot loader and the kernel will use whichever console is indicated by in the boot block. See &man.loader.conf.5; for more information. At the moment, the boot loader has no option equivalent to in the boot block, and there is no provision to automatically select the internal console and the serial console based on the presence of the keyboard. While it is not required, it is possible to provide a login prompt over the serial line. To configure this, edit the entry for the serial port in /etc/ttys using the instructions in . If the speed of the serial port has been changed, change std.9600 to match the new setting. Setting a Faster Serial Port Speed By default, the serial port settings are 9600 baud, 8 bits, no parity, and 1 stop bit. To change the default console speed, use one of the following options: Edit /etc/make.conf and set BOOT_COMCONSOLE_SPEED to the new console speed. Then, recompile and install the boot blocks and the boot loader: &prompt.root; cd /sys/boot &prompt.root; make clean &prompt.root; make &prompt.root; make install If the serial console is configured in some other way than by booting with , or if the serial console used by the kernel is different from the one used by the boot blocks, add the following option, with the desired speed, to a custom kernel configuration file and compile a new kernel: options CONSPEED=19200 Add the boot option to /boot.config, replacing 19200 with the speed to use. Add the following options to /boot/loader.conf. Replace 115200 with the speed to use. boot_multicons="YES" boot_serial="YES" comconsole_speed="115200" console="comconsole,vidconsole" Entering the DDB Debugger from the Serial Line To configure the ability to drop into the kernel debugger from the serial console, add the following options to a custom kernel configuration file and compile the kernel using the instructions in . Note that while this is useful for remote diagnostics, it is also dangerous if a spurious BREAK is generated on the serial port. Refer to &man.ddb.4; and &man.ddb.8; for more information about the kernel debugger. options BREAK_TO_DEBUGGER options DDB