diff --git a/contrib/ntp/ntpd/ntp.conf.def b/contrib/ntp/ntpd/ntp.conf.def index 444e3b35e351..aba3c25ab464 100644 --- a/contrib/ntp/ntpd/ntp.conf.def +++ b/contrib/ntp/ntpd/ntp.conf.def @@ -1,3306 +1,3306 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include copyright.def // We want the synopsis to be "/etc/ntp.conf" but we need the prog-name // to be ntp.conf - the latter is also how autogen produces the output // file name. prog-name = "ntp.conf"; file-path = "/etc/ntp.conf"; -prog-title = "Network Time Protocol (NTP) daemon configuration file format"; +prog-title = "Network Time Protocol daemon (ntpd) configuration format"; /* explain: Additional information whenever the usage routine is invoked */ explain = <<- _END_EXPLAIN _END_EXPLAIN; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP The .Nm configuration file is read at initial startup by the .Xr ntpd 1ntpdmdoc daemon in order to specify the synchronization sources, modes and other related information. Usually, it is installed in the .Pa /etc directory, but could be installed elsewhere (see the daemon's .Fl c command line option). .Pp The file format is similar to other .Ux configuration files. Comments begin with a .Ql # character and extend to the end of the line; blank lines are ignored. Configuration commands consist of an initial keyword followed by a list of arguments, some of which may be optional, separated by whitespace. Commands may not be continued over multiple lines. Arguments may be host names, host addresses written in numeric, dotted-quad form, integers, floating point numbers (when specifying times in seconds) and text strings. .Pp The rest of this page describes the configuration and control options. The .Qq Notes on Configuring NTP and Setting up an NTP Subnet page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) contains an extended discussion of these options. In addition to the discussion of general .Sx Configuration Options , there are sections describing the following supported functionality and the options used to control it: .Bl -bullet -offset indent .It .Sx Authentication Support .It .Sx Monitoring Support .It .Sx Access Control Support .It .Sx Automatic NTP Configuration Options .It .Sx Reference Clock Support .It .Sx Miscellaneous Options .El .Pp Following these is a section describing .Sx Miscellaneous Options . While there is a rich set of options available, the only required option is one or more .Ic pool , .Ic server , .Ic peer , .Ic broadcast or .Ic manycastclient commands. .Sh Configuration Support Following is a description of the configuration commands in NTPv4. These commands have the same basic functions as in NTPv3 and in some cases new functions and new arguments. There are two classes of commands, configuration commands that configure a persistent association with a remote server or peer or reference clock, and auxiliary commands that specify environmental variables that control various related operations. .Ss Configuration Commands The various modes are determined by the command keyword and the type of the required IP address. Addresses are classed by type as (s) a remote server or peer (IPv4 class A, B and C), (b) the broadcast address of a local interface, (m) a multicast address (IPv4 class D), or (r) a reference clock address (127.127.x.x). Note that only those options applicable to each command are listed below. Use of options not listed may not be caught as an error, but may result in some weird and even destructive behavior. .Pp If the Basic Socket Interface Extensions for IPv6 (RFC-2553) is detected, support for the IPv6 address family is generated in addition to the default support of the IPv4 address family. In a few cases, including the .Cm reslist billboard generated by .Xr ntpq 1ntpqmdoc or .Xr ntpdc 1ntpdcmdoc , IPv6 addresses are automatically generated. IPv6 addresses can be identified by the presence of colons .Dq \&: in the address field. IPv6 addresses can be used almost everywhere where IPv4 addresses can be used, with the exception of reference clock addresses, which are always IPv4. .Pp Note that in contexts where a host name is expected, a .Fl 4 qualifier preceding the host name forces DNS resolution to the IPv4 namespace, while a .Fl 6 qualifier forces DNS resolution to the IPv6 namespace. See IPv6 references for the equivalent classes for that address family. .Bl -tag -width indent .It Xo Ic pool Ar address .Op Cm burst .Op Cm iburst .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm xmtnonce .Xc .It Xo Ic server Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm burst .Op Cm iburst .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm true .Op Cm xmtnonce .Xc .It Xo Ic peer Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm true .Op Cm xleave .Xc .It Xo Ic broadcast Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm ttl Ar ttl .Op Cm xleave .Xc .It Xo Ic manycastclient Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm ttl Ar ttl .Xc .El .Pp These five commands specify the time server name or address to be used and the mode in which to operate. The .Ar address can be either a DNS name or an IP address in dotted-quad notation. Additional information on association behavior can be found in the .Qq Association Management page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Bl -tag -width indent .It Ic pool For type s addresses, this command mobilizes a persistent client mode association with a number of remote servers. In this mode the local clock can synchronized to the remote server, but the remote server can never be synchronized to the local clock. .It Ic server For type s and r addresses, this command mobilizes a persistent client mode association with the specified remote server or local radio clock. In this mode the local clock can synchronized to the remote server, but the remote server can never be synchronized to the local clock. This command should .Em not be used for type b or m addresses. .It Ic peer For type s addresses (only), this command mobilizes a persistent symmetric-active mode association with the specified remote peer. In this mode the local clock can be synchronized to the remote peer or the remote peer can be synchronized to the local clock. This is useful in a network of servers where, depending on various failure scenarios, either the local or remote peer may be the better source of time. This command should NOT be used for type b, m or r addresses. .It Ic broadcast For type b and m addresses (only), this command mobilizes a persistent broadcast mode association. Multiple commands can be used to specify multiple local broadcast interfaces (subnets) and/or multiple multicast groups. Note that local broadcast messages go only to the interface associated with the subnet specified, but multicast messages go to all interfaces. In broadcast mode the local server sends periodic broadcast messages to a client population at the .Ar address specified, which is usually the broadcast address on (one of) the local network(s) or a multicast address assigned to NTP. The IANA has assigned the multicast group address IPv4 224.0.1.1 and IPv6 ff05::101 (site local) exclusively to NTP, but other nonconflicting addresses can be used to contain the messages within administrative boundaries. Ordinarily, this specification applies only to the local server operating as a sender; for operation as a broadcast client, see the .Ic broadcastclient or .Ic multicastclient commands below. .It Ic manycastclient For type m addresses (only), this command mobilizes a manycast client mode association for the multicast address specified. In this case a specific address must be supplied which matches the address used on the .Ic manycastserver command for the designated manycast servers. The NTP multicast address 224.0.1.1 assigned by the IANA should NOT be used, unless specific means are taken to avoid spraying large areas of the Internet with these messages and causing a possibly massive implosion of replies at the sender. The .Ic manycastserver command specifies that the local server is to operate in client mode with the remote servers that are discovered as the result of broadcast/multicast messages. The client broadcasts a request message to the group address associated with the specified .Ar address and specifically enabled servers respond to these messages. The client selects the servers providing the best time and continues as with the .Ic server command. The remaining servers are discarded as if never heard. .El .Pp Options: .Bl -tag -width indent .It Cm autokey All packets sent to and received from the server or peer are to include authentication fields encrypted using the autokey scheme described in .Sx Authentication Options . .It Cm burst when the server is reachable, send a burst of six packets instead of the usual one. The packet spacing is 2 s. This is designed to improve timekeeping quality with the .Ic server command and s addresses. .It Cm iburst When the server is unreachable, send a burst of eight packets instead of the usual one. The packet spacing is 2 s. This is designed to speed the initial synchronization acquisition with the .Ic server command and s addresses and when .Xr ntpd 1ntpdmdoc is started with the .Fl q option. .It Cm key Ar key All packets sent to and received from the server or peer are to include authentication fields encrypted using the specified .Ar key identifier with values from 1 to 65535, inclusive. The default is to include no encryption field. .It Cm minpoll Ar minpoll .It Cm maxpoll Ar maxpoll These options specify the minimum and maximum poll intervals for NTP messages, as a power of 2 in seconds The maximum poll interval defaults to 10 (1,024 s), but can be increased by the .Cm maxpoll option to an upper limit of 17 (36.4 h). The minimum poll interval defaults to 6 (64 s), but can be decreased by the .Cm minpoll option to a lower limit of 4 (16 s). .It Cm noselect Marks the server as unused, except for display purposes. The server is discarded by the selection algroithm. .It Cm preempt Says the association can be preempted. .It Cm prefer Marks the server as preferred. All other things being equal, this host will be chosen for synchronization among a set of correctly operating hosts. See the .Qq Mitigation Rules and the prefer Keyword page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) for further information. .It Cm true Marks the server as a truechimer, forcing the association to always survive the selection and clustering algorithms. This option should almost certainly .Em only be used while testing an association. .It Cm ttl Ar ttl This option is used only with broadcast server and manycast client modes. It specifies the time-to-live .Ar ttl to use on broadcast server and multicast server and the maximum .Ar ttl for the expanding ring search with manycast client packets. Selection of the proper value, which defaults to 127, is something of a black art and should be coordinated with the network administrator. .It Cm version Ar version Specifies the version number to be used for outgoing NTP packets. Versions 1-4 are the choices, with version 4 the default. .It Cm xleave Valid in .Cm peer and .Cm broadcast modes only, this flag enables interleave mode. .It Cm xmtnonce Valid only for .Cm server and .Cm pool modes, this flag puts a random number in the packet's transmit timestamp. .El .Ss Auxiliary Commands .Bl -tag -width indent .It Ic broadcastclient This command enables reception of broadcast server messages to any local interface (type b) address. Upon receiving a message for the first time, the broadcast client measures the nominal server propagation delay using a brief client/server exchange with the server, then enters the broadcast client mode, in which it synchronizes to succeeding broadcast messages. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric-key or public-key authentication as described in .Sx Authentication Options . .It Ic manycastserver Ar address ... This command enables reception of manycast client messages to the multicast group address(es) (type m) specified. At least one address is required, but the NTP multicast address 224.0.1.1 assigned by the IANA should NOT be used, unless specific means are taken to limit the span of the reply and avoid a possibly massive implosion at the original sender. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric-key or public-key authentication as described in .Sx Authentication Options . .It Ic multicastclient Ar address ... This command enables reception of multicast server messages to the multicast group address(es) (type m) specified. Upon receiving a message for the first time, the multicast client measures the nominal server propagation delay using a brief client/server exchange with the server, then enters the broadcast client mode, in which it synchronizes to succeeding multicast messages. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric-key or public-key authentication as described in .Sx Authentication Options . .It Ic mdnstries Ar number If we are participating in mDNS, after we have synched for the first time we attempt to register with the mDNS system. If that registration attempt fails, we try again at one minute intervals for up to .Ic mdnstries times. After all, .Ic ntpd may be starting before mDNS. The default value for .Ic mdnstries is 5. .El .Sh Authentication Support Authentication support allows the NTP client to verify that the server is in fact known and trusted and not an intruder intending accidentally or on purpose to masquerade as that server. The NTPv3 specification RFC-1305 defines a scheme which provides cryptographic authentication of received NTP packets. Originally, this was done using the Data Encryption Standard (DES) algorithm operating in Cipher Block Chaining (CBC) mode, commonly called DES-CBC. Subsequently, this was replaced by the RSA Message Digest 5 (MD5) algorithm using a private key, commonly called keyed-MD5. Either algorithm computes a message digest, or one-way hash, which can be used to verify the server has the correct private key and key identifier. .Pp NTPv4 retains the NTPv3 scheme, properly described as symmetric key cryptography and, in addition, provides a new Autokey scheme based on public key cryptography. Public key cryptography is generally considered more secure than symmetric key cryptography, since the security is based on a private value which is generated by each server and never revealed. With Autokey all key distribution and management functions involve only public values, which considerably simplifies key distribution and storage. Public key management is based on X.509 certificates, which can be provided by commercial services or produced by utility programs in the OpenSSL software library or the NTPv4 distribution. .Pp While the algorithms for symmetric key cryptography are included in the NTPv4 distribution, public key cryptography requires the OpenSSL software library to be installed before building the NTP distribution. Directions for doing that are on the Building and Installing the Distribution page. .Pp Authentication is configured separately for each association using the .Cm key or .Cm autokey subcommand on the .Ic peer , .Ic server , .Ic broadcast and .Ic manycastclient configuration commands as described in .Sx Configuration Options page. The authentication options described below specify the locations of the key files, if other than default, which symmetric keys are trusted and the interval between various operations, if other than default. .Pp Authentication is always enabled, although ineffective if not configured as described below. If a NTP packet arrives including a message authentication code (MAC), it is accepted only if it passes all cryptographic checks. The checks require correct key ID, key value and message digest. If the packet has been modified in any way or replayed by an intruder, it will fail one or more of these checks and be discarded. Furthermore, the Autokey scheme requires a preliminary protocol exchange to obtain the server certificate, verify its credentials and initialize the protocol .Pp The .Cm auth flag controls whether new associations or remote configuration commands require cryptographic authentication. This flag can be set or reset by the .Ic enable and .Ic disable commands and also by remote configuration commands sent by a .Xr ntpdc 1ntpdcmdoc program running on another machine. If this flag is enabled, which is the default case, new broadcast client and symmetric passive associations and remote configuration commands must be cryptographically authenticated using either symmetric key or public key cryptography. If this flag is disabled, these operations are effective even if not cryptographic authenticated. It should be understood that operating with the .Ic auth flag disabled invites a significant vulnerability where a rogue hacker can masquerade as a falseticker and seriously disrupt system timekeeping. It is important to note that this flag has no purpose other than to allow or disallow a new association in response to new broadcast and symmetric active messages and remote configuration commands and, in particular, the flag has no effect on the authentication process itself. .Pp An attractive alternative where multicast support is available is manycast mode, in which clients periodically troll for servers as described in the .Sx Automatic NTP Configuration Options page. Either symmetric key or public key cryptographic authentication can be used in this mode. The principle advantage of manycast mode is that potential servers need not be configured in advance, since the client finds them during regular operation, and the configuration files for all clients can be identical. .Pp The security model and protocol schemes for both symmetric key and public key cryptography are summarized below; further details are in the briefings, papers and reports at the NTP project page linked from .Li http://www.ntp.org/ . .Ss Symmetric-Key Cryptography The original RFC-1305 specification allows any one of possibly 65,535 keys, each distinguished by a 32-bit key identifier, to authenticate an association. The servers and clients involved must agree on the key and key identifier to authenticate NTP packets. Keys and related information are specified in a key file, usually called .Pa ntp.keys , which must be distributed and stored using secure means beyond the scope of the NTP protocol itself. Besides the keys used for ordinary NTP associations, additional keys can be used as passwords for the .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc utility programs. .Pp When .Xr ntpd 1ntpdmdoc is first started, it reads the key file specified in the .Ic keys configuration command and installs the keys in the key cache. However, individual keys must be activated with the .Ic trusted command before use. This allows, for instance, the installation of possibly several batches of keys and then activating or deactivating each batch remotely using .Xr ntpdc 1ntpdcmdoc . This also provides a revocation capability that can be used if a key becomes compromised. The .Ic requestkey command selects the key used as the password for the .Xr ntpdc 1ntpdcmdoc utility, while the .Ic controlkey command selects the key used as the password for the .Xr ntpq 1ntpqmdoc utility. .Ss Public Key Cryptography NTPv4 supports the original NTPv3 symmetric key scheme described in RFC-1305 and in addition the Autokey protocol, which is based on public key cryptography. The Autokey Version 2 protocol described on the Autokey Protocol page verifies packet integrity using MD5 message digests and verifies the source with digital signatures and any of several digest/signature schemes. Optional identity schemes described on the Identity Schemes page and based on cryptographic challenge/response algorithms are also available. Using all of these schemes provides strong security against replay with or without modification, spoofing, masquerade and most forms of clogging attacks. .\" .Pp .\" The cryptographic means necessary for all Autokey operations .\" is provided by the OpenSSL software library. .\" This library is available from http://www.openssl.org/ .\" and can be installed using the procedures outlined .\" in the Building and Installing the Distribution page. .\" Once installed, .\" the configure and build .\" process automatically detects the library and links .\" the library routines required. .Pp The Autokey protocol has several modes of operation corresponding to the various NTP modes supported. Most modes use a special cookie which can be computed independently by the client and server, but encrypted in transmission. All modes use in addition a variant of the S-KEY scheme, in which a pseudo-random key list is generated and used in reverse order. These schemes are described along with an executive summary, current status, briefing slides and reading list on the .Sx Autonomous Authentication page. .Pp The specific cryptographic environment used by Autokey servers and clients is determined by a set of files and soft links generated by the .Xr ntp-keygen 1ntpkeygenmdoc program. This includes a required host key file, required certificate file and optional sign key file, leapsecond file and identity scheme files. The digest/signature scheme is specified in the X.509 certificate along with the matching sign key. There are several schemes available in the OpenSSL software library, each identified by a specific string such as .Cm md5WithRSAEncryption , which stands for the MD5 message digest with RSA encryption scheme. The current NTP distribution supports all the schemes in the OpenSSL library, including those based on RSA and DSA digital signatures. .Pp NTP secure groups can be used to define cryptographic compartments and security hierarchies. It is important that every host in the group be able to construct a certificate trail to one or more trusted hosts in the same group. Each group host runs the Autokey protocol to obtain the certificates for all hosts along the trail to one or more trusted hosts. This requires the configuration file in all hosts to be engineered so that, even under anticipated failure conditions, the NTP subnet will form such that every group host can find a trail to at least one trusted host. .Ss Naming and Addressing It is important to note that Autokey does not use DNS to resolve addresses, since DNS can't be completely trusted until the name servers have synchronized clocks. The cryptographic name used by Autokey to bind the host identity credentials and cryptographic values must be independent of interface, network and any other naming convention. The name appears in the host certificate in either or both the subject and issuer fields, so protection against DNS compromise is essential. .Pp By convention, the name of an Autokey host is the name returned by the Unix .Xr gethostname 2 system call or equivalent in other systems. By the system design model, there are no provisions to allow alternate names or aliases. However, this is not to say that DNS aliases, different names for each interface, etc., are constrained in any way. .Pp It is also important to note that Autokey verifies authenticity using the host name, network address and public keys, all of which are bound together by the protocol specifically to deflect masquerade attacks. For this reason Autokey includes the source and destination IP addresses in message digest computations and so the same addresses must be available at both the server and client. For this reason operation with network address translation schemes is not possible. This reflects the intended robust security model where government and corporate NTP servers are operated outside firewall perimeters. .Ss Operation A specific combination of authentication scheme (none, symmetric key, public key) and identity scheme is called a cryptotype, although not all combinations are compatible. There may be management configurations where the clients, servers and peers may not all support the same cryptotypes. A secure NTPv4 subnet can be configured in many ways while keeping in mind the principles explained above and in this section. Note however that some cryptotype combinations may successfully interoperate with each other, but may not represent good security practice. .Pp The cryptotype of an association is determined at the time of mobilization, either at configuration time or some time later when a message of appropriate cryptotype arrives. When mobilized by a .Ic server or .Ic peer configuration command and no .Ic key or .Ic autokey subcommands are present, the association is not authenticated; if the .Ic key subcommand is present, the association is authenticated using the symmetric key ID specified; if the .Ic autokey subcommand is present, the association is authenticated using Autokey. .Pp When multiple identity schemes are supported in the Autokey protocol, the first message exchange determines which one is used. The client request message contains bits corresponding to which schemes it has available. The server response message contains bits corresponding to which schemes it has available. Both server and client match the received bits with their own and select a common scheme. .Pp Following the principle that time is a public value, a server responds to any client packet that matches its cryptotype capabilities. Thus, a server receiving an unauthenticated packet will respond with an unauthenticated packet, while the same server receiving a packet of a cryptotype it supports will respond with packets of that cryptotype. However, unconfigured broadcast or manycast client associations or symmetric passive associations will not be mobilized unless the server supports a cryptotype compatible with the first packet received. By default, unauthenticated associations will not be mobilized unless overridden in a decidedly dangerous way. .Pp Some examples may help to reduce confusion. Client Alice has no specific cryptotype selected. Server Bob has both a symmetric key file and minimal Autokey files. Alice's unauthenticated messages arrive at Bob, who replies with unauthenticated messages. Cathy has a copy of Bob's symmetric key file and has selected key ID 4 in messages to Bob. Bob verifies the message with his key ID 4. If it's the same key and the message is verified, Bob sends Cathy a reply authenticated with that key. If verification fails, Bob sends Cathy a thing called a crypto-NAK, which tells her something broke. She can see the evidence using the .Xr ntpq 1ntpqmdoc program. .Pp Denise has rolled her own host key and certificate. She also uses one of the identity schemes as Bob. She sends the first Autokey message to Bob and they both dance the protocol authentication and identity steps. If all comes out okay, Denise and Bob continue as described above. .Pp It should be clear from the above that Bob can support all the girls at the same time, as long as he has compatible authentication and identity credentials. Now, Bob can act just like the girls in his own choice of servers; he can run multiple configured associations with multiple different servers (or the same server, although that might not be useful). But, wise security policy might preclude some cryptotype combinations; for instance, running an identity scheme with one server and no authentication with another might not be wise. .Ss Key Management The cryptographic values used by the Autokey protocol are incorporated as a set of files generated by the .Xr ntp-keygen 1ntpkeygenmdoc utility program, including symmetric key, host key and public certificate files, as well as sign key, identity parameters and leapseconds files. Alternatively, host and sign keys and certificate files can be generated by the OpenSSL utilities and certificates can be imported from public certificate authorities. Note that symmetric keys are necessary for the .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc utility programs. The remaining files are necessary only for the Autokey protocol. .Pp Certificates imported from OpenSSL or public certificate authorities have certian limitations. The certificate should be in ASN.1 syntax, X.509 Version 3 format and encoded in PEM, which is the same format used by OpenSSL. The overall length of the certificate encoded in ASN.1 must not exceed 1024 bytes. The subject distinguished name field (CN) is the fully qualified name of the host on which it is used; the remaining subject fields are ignored. The certificate extension fields must not contain either a subject key identifier or a issuer key identifier field; however, an extended key usage field for a trusted host must contain the value .Cm trustRoot ; . Other extension fields are ignored. .Ss Authentication Commands .Bl -tag -width indent .It Ic autokey Op Ar logsec Specifies the interval between regenerations of the session key list used with the Autokey protocol. Note that the size of the key list for each association depends on this interval and the current poll interval. The default value is 12 (4096 s or about 1.1 hours). For poll intervals above the specified interval, a session key list with a single entry will be regenerated for every message sent. .It Ic controlkey Ar key Specifies the key identifier to use with the .Xr ntpq 1ntpqmdoc utility, which uses the standard protocol defined in RFC-1305. The .Ar key argument is the key identifier for a trusted key, where the value can be in the range 1 to 65,535, inclusive. .It Xo Ic crypto .Op Cm cert Ar file .Op Cm leap Ar file .Op Cm randfile Ar file .Op Cm host Ar file .Op Cm gq Ar file .Op Cm gqpar Ar file .Op Cm iffpar Ar file .Op Cm mvpar Ar file .Op Cm pw Ar password .Xc This command requires the OpenSSL library. It activates public key cryptography, selects the message digest and signature encryption scheme and loads the required private and public values described above. If one or more files are left unspecified, the default names are used as described above. Unless the complete path and name of the file are specified, the location of a file is relative to the keys directory specified in the .Ic keysdir command or default .Pa /usr/local/etc . Following are the subcommands: .Bl -tag -width indent .It Cm cert Ar file Specifies the location of the required host public certificate file. This overrides the link .Pa ntpkey_cert_ Ns Ar hostname in the keys directory. .It Cm gqpar Ar file Specifies the location of the optional GQ parameters file. This overrides the link .Pa ntpkey_gq_ Ns Ar hostname in the keys directory. .It Cm host Ar file Specifies the location of the required host key file. This overrides the link .Pa ntpkey_key_ Ns Ar hostname in the keys directory. .It Cm iffpar Ar file Specifies the location of the optional IFF parameters file. This overrides the link .Pa ntpkey_iff_ Ns Ar hostname in the keys directory. .It Cm leap Ar file Specifies the location of the optional leapsecond file. This overrides the link .Pa ntpkey_leap in the keys directory. .It Cm mvpar Ar file Specifies the location of the optional MV parameters file. This overrides the link .Pa ntpkey_mv_ Ns Ar hostname in the keys directory. .It Cm pw Ar password Specifies the password to decrypt files containing private keys and identity parameters. This is required only if these files have been encrypted. .It Cm randfile Ar file Specifies the location of the random seed file used by the OpenSSL library. The defaults are described in the main text above. .El .It Ic keys Ar keyfile Specifies the complete path and location of the MD5 key file containing the keys and key identifiers used by .Xr ntpd 1ntpdmdoc , .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc when operating with symmetric key cryptography. This is the same operation as the .Fl k command line option. .It Ic keysdir Ar path This command specifies the default directory path for cryptographic keys, parameters and certificates. The default is .Pa /usr/local/etc/ . .It Ic requestkey Ar key Specifies the key identifier to use with the .Xr ntpdc 1ntpdcmdoc utility program, which uses a proprietary protocol specific to this implementation of .Xr ntpd 1ntpdmdoc . The .Ar key argument is a key identifier for the trusted key, where the value can be in the range 1 to 65,535, inclusive. .It Ic revoke Ar logsec Specifies the interval between re-randomization of certain cryptographic values used by the Autokey scheme, as a power of 2 in seconds. These values need to be updated frequently in order to deflect brute-force attacks on the algorithms of the scheme; however, updating some values is a relatively expensive operation. The default interval is 16 (65,536 s or about 18 hours). For poll intervals above the specified interval, the values will be updated for every message sent. .It Ic trustedkey Ar key ... Specifies the key identifiers which are trusted for the purposes of authenticating peers with symmetric key cryptography, as well as keys used by the .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc programs. The authentication procedures require that both the local and remote servers share the same key and key identifier for this purpose, although different keys can be used with different servers. The .Ar key arguments are 32-bit unsigned integers with values from 1 to 65,535. .El .Ss Error Codes The following error codes are reported via the NTP control and monitoring protocol trap mechanism. .Bl -tag -width indent .It 101 .Pq bad field format or length The packet has invalid version, length or format. .It 102 .Pq bad timestamp The packet timestamp is the same or older than the most recent received. This could be due to a replay or a server clock time step. .It 103 .Pq bad filestamp The packet filestamp is the same or older than the most recent received. This could be due to a replay or a key file generation error. .It 104 .Pq bad or missing public key The public key is missing, has incorrect format or is an unsupported type. .It 105 .Pq unsupported digest type The server requires an unsupported digest/signature scheme. .It 106 .Pq mismatched digest types Not used. .It 107 .Pq bad signature length The signature length does not match the current public key. .It 108 .Pq signature not verified The message fails the signature check. It could be bogus or signed by a different private key. .It 109 .Pq certificate not verified The certificate is invalid or signed with the wrong key. .It 110 .Pq certificate not verified The certificate is not yet valid or has expired or the signature could not be verified. .It 111 .Pq bad or missing cookie The cookie is missing, corrupted or bogus. .It 112 .Pq bad or missing leapseconds table The leapseconds table is missing, corrupted or bogus. .It 113 .Pq bad or missing certificate The certificate is missing, corrupted or bogus. .It 114 .Pq bad or missing identity The identity key is missing, corrupt or bogus. .El .Sh Monitoring Support .Xr ntpd 1ntpdmdoc includes a comprehensive monitoring facility suitable for continuous, long term recording of server and client timekeeping performance. See the .Ic statistics command below for a listing and example of each type of statistics currently supported. Statistic files are managed using file generation sets and scripts in the .Pa ./scripts directory of the source code distribution. Using these facilities and .Ux .Xr cron 8 jobs, the data can be automatically summarized and archived for retrospective analysis. .Ss Monitoring Commands .Bl -tag -width indent .It Ic statistics Ar name ... Enables writing of statistics records. Currently, eight kinds of .Ar name statistics are supported. .Bl -tag -width indent .It Cm clockstats Enables recording of clock driver statistics information. Each update received from a clock driver appends a line of the following form to the file generation set named .Cm clockstats : .Bd -literal 49213 525.624 127.127.4.1 93 226 00:08:29.606 D .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next field shows the clock address in dotted-quad notation. The final field shows the last timecode received from the clock in decoded ASCII format, where meaningful. In some clock drivers a good deal of additional information can be gathered and displayed as well. See information specific to each clock for further details. .It Cm cryptostats This option requires the OpenSSL cryptographic software library. It enables recording of cryptographic public key protocol information. Each message received by the protocol module appends a line of the following form to the file generation set named .Cm cryptostats : .Bd -literal 49213 525.624 127.127.4.1 message .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next field shows the peer address in dotted-quad notation, The final message field includes the message type and certain ancillary information. See the .Sx Authentication Options section for further information. .It Cm loopstats Enables recording of loop filter statistics information. Each update of the local clock outputs a line of the following form to the file generation set named .Cm loopstats : .Bd -literal 50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next five fields show time offset (seconds), frequency offset (parts per million - PPM), RMS jitter (seconds), Allan deviation (PPM) and clock discipline time constant. .It Cm peerstats Enables recording of peer statistics information. This includes statistics records of all peers of a NTP server and of special signals, where present and configured. Each valid update appends a line of the following form to the current element of a file generation set named .Cm peerstats : .Bd -literal 48773 10847.650 127.127.4.1 9714 -0.001605376 0.000000000 0.001424877 0.000958674 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next two fields show the peer address in dotted-quad notation and status, respectively. The status field is encoded in hex in the format described in Appendix A of the NTP specification RFC 1305. The final four fields show the offset, delay, dispersion and RMS jitter, all in seconds. .It Cm rawstats Enables recording of raw-timestamp statistics information. This includes statistics records of all peers of a NTP server and of special signals, where present and configured. Each NTP message received from a peer or clock driver appends a line of the following form to the file generation set named .Cm rawstats : .Bd -literal 50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next two fields show the remote peer or clock address followed by the local address in dotted-quad notation. The final four fields show the originate, receive, transmit and final NTP timestamps in order. The timestamp values are as received and before processing by the various data smoothing and mitigation algorithms. .It Cm sysstats Enables recording of ntpd statistics counters on a periodic basis. Each hour a line of the following form is appended to the file generation set named .Cm sysstats : .Bd -literal 50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The remaining ten fields show the statistics counter values accumulated since the last generated line. .Bl -tag -width indent .It Time since restart Cm 36000 Time in hours since the system was last rebooted. .It Packets received Cm 81965 Total number of packets received. .It Packets processed Cm 0 Number of packets received in response to previous packets sent .It Current version Cm 9546 Number of packets matching the current NTP version. .It Previous version Cm 56 Number of packets matching the previous NTP version. .It Bad version Cm 71793 Number of packets matching neither NTP version. .It Access denied Cm 512 Number of packets denied access for any reason. .It Bad length or format Cm 540 Number of packets with invalid length, format or port number. .It Bad authentication Cm 10 Number of packets not verified as authentic. .It Rate exceeded Cm 147 Number of packets discarded due to rate limitation. .El .It Cm statsdir Ar directory_path Indicates the full path of a directory where statistics files should be created (see below). This keyword allows the (otherwise constant) .Cm filegen filename prefix to be modified for file generation sets, which is useful for handling statistics logs. .It Cm filegen Ar name Xo .Op Cm file Ar filename .Op Cm type Ar typename .Op Cm link | nolink .Op Cm enable | disable .Xc Configures setting of generation file set name. Generation file sets provide a means for handling files that are continuously growing during the lifetime of a server. Server statistics are a typical example for such files. Generation file sets provide access to a set of files used to store the actual data. At any time at most one element of the set is being written to. The type given specifies when and how data will be directed to a new element of the set. This way, information stored in elements of a file set that are currently unused are available for administrational operations without the risk of disturbing the operation of ntpd. (Most important: they can be removed to free space for new data produced.) .Pp Note that this command can be sent from the .Xr ntpdc 1ntpdcmdoc program running at a remote location. .Bl -tag -width indent .It Cm name This is the type of the statistics records, as shown in the .Cm statistics command. .It Cm file Ar filename This is the file name for the statistics records. Filenames of set members are built from three concatenated elements .Ar Cm prefix , .Ar Cm filename and .Ar Cm suffix : .Bl -tag -width indent .It Cm prefix This is a constant filename path. It is not subject to modifications via the .Ar filegen option. It is defined by the server, usually specified as a compile-time constant. It may, however, be configurable for individual file generation sets via other commands. For example, the prefix used with .Ar loopstats and .Ar peerstats generation can be configured using the .Ar statsdir option explained above. .It Cm filename This string is directly concatenated to the prefix mentioned above (no intervening .Ql / ) . This can be modified using the file argument to the .Ar filegen statement. No .Pa .. elements are allowed in this component to prevent filenames referring to parts outside the filesystem hierarchy denoted by .Ar prefix . .It Cm suffix This part is reflects individual elements of a file set. It is generated according to the type of a file set. .El .It Cm type Ar typename A file generation set is characterized by its type. The following types are supported: .Bl -tag -width indent .It Cm none The file set is actually a single plain file. .It Cm pid One element of file set is used per incarnation of a ntpd server. This type does not perform any changes to file set members during runtime, however it provides an easy way of separating files belonging to different .Xr ntpd 1ntpdmdoc server incarnations. The set member filename is built by appending a .Ql \&. to concatenated .Ar prefix and .Ar filename strings, and appending the decimal representation of the process ID of the .Xr ntpd 1ntpdmdoc server process. .It Cm day One file generation set element is created per day. A day is defined as the period between 00:00 and 24:00 UTC. The file set member suffix consists of a .Ql \&. and a day specification in the form .Cm YYYYMMdd . .Cm YYYY is a 4-digit year number (e.g., 1992). .Cm MM is a two digit month number. .Cm dd is a two digit day number. Thus, all information written at 10 December 1992 would end up in a file named .Ar prefix .Ar filename Ns .19921210 . .It Cm week Any file set member contains data related to a certain week of a year. The term week is defined by computing day-of-year modulo 7. Elements of such a file generation set are distinguished by appending the following suffix to the file set filename base: A dot, a 4-digit year number, the letter .Cm W , and a 2-digit week number. For example, information from January, 10th 1992 would end up in a file with suffix .No . Ns Ar 1992W1 . .It Cm month One generation file set element is generated per month. The file name suffix consists of a dot, a 4-digit year number, and a 2-digit month. .It Cm year One generation file element is generated per year. The filename suffix consists of a dot and a 4 digit year number. .It Cm age This type of file generation sets changes to a new element of the file set every 24 hours of server operation. The filename suffix consists of a dot, the letter .Cm a , and an 8-digit number. This number is taken to be the number of seconds the server is running at the start of the corresponding 24-hour period. Information is only written to a file generation by specifying .Cm enable ; output is prevented by specifying .Cm disable . .El .It Cm link | nolink It is convenient to be able to access the current element of a file generation set by a fixed name. This feature is enabled by specifying .Cm link and disabled using .Cm nolink . If link is specified, a hard link from the current file set element to a file without suffix is created. When there is already a file with this name and the number of links of this file is one, it is renamed appending a dot, the letter .Cm C , and the pid of the .Xr ntpd 1ntpdmdoc server process. When the number of links is greater than one, the file is unlinked. This allows the current file to be accessed by a constant name. .It Cm enable \&| Cm disable Enables or disables the recording function. .El .El .El .Sh Access Control Support The .Xr ntpd 1ntpdmdoc daemon implements a general purpose address/mask based restriction list. The list contains address/match entries sorted first by increasing address values and and then by increasing mask values. A match occurs when the bitwise AND of the mask and the packet source address is equal to the bitwise AND of the mask and address in the list. The list is searched in order with the last match found defining the restriction flags associated with the entry. Additional information and examples can be found in the .Qq Notes on Configuring NTP and Setting up a NTP Subnet page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Pp The restriction facility was implemented in conformance with the access policies for the original NSFnet backbone time servers. Later the facility was expanded to deflect cryptographic and clogging attacks. While this facility may be useful for keeping unwanted or broken or malicious clients from congesting innocent servers, it should not be considered an alternative to the NTP authentication facilities. Source address based restrictions are easily circumvented by a determined cracker. .Pp Clients can be denied service because they are explicitly included in the restrict list created by the .Ic restrict command or implicitly as the result of cryptographic or rate limit violations. Cryptographic violations include certificate or identity verification failure; rate limit violations generally result from defective NTP implementations that send packets at abusive rates. Some violations cause denied service only for the offending packet, others cause denied service for a timed period and others cause the denied service for an indefinite period. When a client or network is denied access for an indefinite period, the only way at present to remove the restrictions is by restarting the server. .Ss The Kiss-of-Death Packet Ordinarily, packets denied service are simply dropped with no further action except incrementing statistics counters. Sometimes a more proactive response is needed, such as a server message that explicitly requests the client to stop sending and leave a message for the system operator. A special packet format has been created for this purpose called the "kiss-of-death" (KoD) packet. KoD packets have the leap bits set unsynchronized and stratum set to zero and the reference identifier field set to a four-byte ASCII code. If the .Cm noserve or .Cm notrust flag of the matching restrict list entry is set, the code is "DENY"; if the .Cm limited flag is set and the rate limit is exceeded, the code is "RATE". Finally, if a cryptographic violation occurs, the code is "CRYP". .Pp A client receiving a KoD performs a set of sanity checks to minimize security exposure, then updates the stratum and reference identifier peer variables, sets the access denied (TEST4) bit in the peer flash variable and sends a message to the log. As long as the TEST4 bit is set, the client will send no further packets to the server. The only way at present to recover from this condition is to restart the protocol at both the client and server. This happens automatically at the client when the association times out. It will happen at the server only if the server operator cooperates. .Ss Access Control Commands .Bl -tag -width indent .It Xo Ic discard .Op Cm average Ar avg .Op Cm minimum Ar min .Op Cm monitor Ar prob .Xc Set the parameters of the .Cm limited facility which protects the server from client abuse. The .Cm average subcommand specifies the minimum average packet spacing in log2 seconds, defaulting to 3 (8s), while the .Cm minimum subcommand specifies the minimum packet spacing in seconds, defaulting to 2. Packets that violate these minima are discarded and a kiss-o'-death packet returned if enabled. The .Ic monitor subcommand indirectly specifies the probability of replacing the oldest entry from the monitor (MRU) list of recent requests used to enforce rate controls, when that list is at its maximum size. The probability of replacing the oldest entry is the age of that entry in seconds divided by the .Ic monitor value, default 3000. For example, if the oldest entry in the MRU list represents a request 300 seconds ago, by default the probability of replacing it with an entry representing the client request being processed now is 10%. Conversely, if the oldest entry is more than 3000 seconds old, the probability is 100%. .It Xo Ic restrict .Ar address .Op Cm mask Ar mask .Op Cm ippeerlimit Ar int .Op Ar flag ... .Xc The .Ar address argument expressed in numeric form is the address of a host or network. Alternatively, the .Ar address argument can be a valid hostname. When a hostname is provided, a restriction entry is created for each address the hostname resolves to, and any provided .Ar mask is ignored and an individual host mask is used for each entry. The .Ar mask argument expressed in numeric form defaults to all bits lit, meaning that the .Ar address is treated as the address of an individual host. A default entry with address and mask all zeroes is always included and is always the first entry in the list. Note that text string .Cm default , with no mask option, may be used to indicate the default entry. The .Cm ippeerlimit directive limits the number of peer requests for each IP to .Ar int , where a value of -1 means "unlimited", the current default. A value of 0 means "none". There would usually be at most 1 peering request per IP, but if the remote peering requests are behind a proxy there could well be more than 1 per IP. In the current implementation, .Cm flag always restricts access, i.e., an entry with no flags indicates that free access to the server is to be given. The flags are not orthogonal, in that more restrictive flags will often make less restrictive ones redundant. The flags can generally be classed into two categories, those which restrict time service and those which restrict informational queries and attempts to do run-time reconfiguration of the server. One or more of the following flags may be specified: .Bl -tag -width indent .It Cm ignore Deny packets of all kinds, including .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc queries. .It Cm kod If this flag is set when a rate violation occurs, a kiss-o'-death (KoD) packet is sometimes sent. KoD packets are rate limited to no more than one per minimum average interpacket spacing, set by .Cm discard average defaulting to 8s. Otherwise, no response is sent. .It Cm limited Deny service if the packet spacing violates the lower limits specified in the .Ic discard command. A history of clients is kept using the monitoring capability of .Xr ntpd 1ntpdmdoc . Thus, monitoring is always active as long as there is a restriction entry with the .Cm limited flag. .It Cm lowpriotrap Declare traps set by matching hosts to be low priority. The number of traps a server can maintain is limited (the current limit is 3). Traps are usually assigned on a first come, first served basis, with later trap requestors being denied service. This flag modifies the assignment algorithm by allowing low priority traps to be overridden by later requests for normal priority traps. .It Cm noepeer Deny ephemeral peer requests, even if they come from an authenticated source. Note that the ability to use a symmetric key for authentication may be restricted to one or more IPs or subnets via the third field of the .Pa ntp.keys file. This restriction is not enabled by default, to maintain backward compatability. Expect .Cm noepeer to become the default in ntp-4.4. .It Cm nomodify Deny .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc queries which attempt to modify the state of the server (i.e., run time reconfiguration). Queries which return information are permitted. .It Cm noquery Deny .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc queries. Time service is not affected. .It Cm nopeer Deny unauthenticated packets which would result in mobilizing a new association. This includes broadcast and symmetric active packets when a configured association does not exist. It also includes .Cm pool associations, so if you want to use servers from a .Cm pool directive and also want to use .Cm nopeer by default, you'll want a .Cm "restrict source ..." line as well that does .Em not include the .Cm nopeer directive. .It Cm noserve Deny all packets except .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc queries. .It Cm notrap Decline to provide mode 6 control message trap service to matching hosts. The trap service is a subsystem of the .Xr ntpq 1ntpqmdoc control message protocol which is intended for use by remote event logging programs. .It Cm notrust Deny service unless the packet is cryptographically authenticated. .It Cm ntpport This is actually a match algorithm modifier, rather than a restriction flag. Its presence causes the restriction entry to be matched only if the source port in the packet is the standard NTP UDP port (123). There can be two restriction entries with the same IP address if one specifies .Cm ntpport and the other does not. The .Cm ntpport entry is considered more specific and is sorted later in the list. .It Ic "serverresponse fuzz" When reponding to server requests, fuzz the low order bits of the .Cm reftime . .It Cm version Deny packets that do not match the current NTP version. .El .Pp Default restriction list entries with the flags ignore, interface, ntpport, for each of the local host's interface addresses are inserted into the table at startup to prevent ntpd from attempting to synchronize to itself, such as with .Cm manycastclient when .Cm manycast is also specified with the same multicast address. A default entry is also always present, though if it is otherwise unconfigured; no flags are associated with the default entry (i.e., everything besides your own NTP server is unrestricted). .It Xo Ic delrestrict .Op source .Ar address .Xc Remove a previously-set restriction. This is useful for runtime configuration via .Xr ntpq 1ntpqmdoc . If .Cm source is specified, a dynamic restriction created from the .Cm restrict source template at the time an association was added is removed. Without .Cm source a static restriction is removed. .El .Sh Automatic NTP Configuration Options .Ss Manycasting Manycasting is a automatic discovery and configuration paradigm new to NTPv4. It is intended as a means for a multicast client to troll the nearby network neighborhood to find cooperating manycast servers, validate them using cryptographic means and evaluate their time values with respect to other servers that might be lurking in the vicinity. The intended result is that each manycast client mobilizes client associations with some number of the "best" of the nearby manycast servers, yet automatically reconfigures to sustain this number of servers should one or another fail. .Pp Note that the manycasting paradigm does not coincide with the anycast paradigm described in RFC-1546, which is designed to find a single server from a clique of servers providing the same service. The manycast paradigm is designed to find a plurality of redundant servers satisfying defined optimality criteria. .Pp Manycasting can be used with either symmetric key or public key cryptography. The public key infrastructure (PKI) offers the best protection against compromised keys and is generally considered stronger, at least with relatively large key sizes. It is implemented using the Autokey protocol and the OpenSSL cryptographic library available from .Li http://www.openssl.org/ . The library can also be used with other NTPv4 modes as well and is highly recommended, especially for broadcast modes. .Pp A persistent manycast client association is configured using the .Ic manycastclient command, which is similar to the .Ic server command but with a multicast (IPv4 class .Cm D or IPv6 prefix .Cm FF ) group address. The IANA has designated IPv4 address 224.1.1.1 and IPv6 address FF05::101 (site local) for NTP. When more servers are needed, it broadcasts manycast client messages to this address at the minimum feasible rate and minimum feasible time-to-live (TTL) hops, depending on how many servers have already been found. There can be as many manycast client associations as different group address, each one serving as a template for a future ephemeral unicast client/server association. .Pp Manycast servers configured with the .Ic manycastserver command listen on the specified group address for manycast client messages. Note the distinction between manycast client, which actively broadcasts messages, and manycast server, which passively responds to them. If a manycast server is in scope of the current TTL and is itself synchronized to a valid source and operating at a stratum level equal to or lower than the manycast client, it replies to the manycast client message with an ordinary unicast server message. .Pp The manycast client receiving this message mobilizes an ephemeral client/server association according to the matching manycast client template, but only if cryptographically authenticated and the server stratum is less than or equal to the client stratum. Authentication is explicitly required and either symmetric key or public key (Autokey) can be used. Then, the client polls the server at its unicast address in burst mode in order to reliably set the host clock and validate the source. This normally results in a volley of eight client/server at 2-s intervals during which both the synchronization and cryptographic protocols run concurrently. Following the volley, the client runs the NTP intersection and clustering algorithms, which act to discard all but the "best" associations according to stratum and synchronization distance. The surviving associations then continue in ordinary client/server mode. .Pp The manycast client polling strategy is designed to reduce as much as possible the volume of manycast client messages and the effects of implosion due to near-simultaneous arrival of manycast server messages. The strategy is determined by the .Ic manycastclient , .Ic tos and .Ic ttl configuration commands. The manycast poll interval is normally eight times the system poll interval, which starts out at the .Cm minpoll value specified in the .Ic manycastclient , command and, under normal circumstances, increments to the .Cm maxpolll value specified in this command. Initially, the TTL is set at the minimum hops specified by the .Ic ttl command. At each retransmission the TTL is increased until reaching the maximum hops specified by this command or a sufficient number client associations have been found. Further retransmissions use the same TTL. .Pp The quality and reliability of the suite of associations discovered by the manycast client is determined by the NTP mitigation algorithms and the .Cm minclock and .Cm minsane values specified in the .Ic tos configuration command. At least .Cm minsane candidate servers must be available and the mitigation algorithms produce at least .Cm minclock survivors in order to synchronize the clock. Byzantine agreement principles require at least four candidates in order to correctly discard a single falseticker. For legacy purposes, .Cm minsane defaults to 1 and .Cm minclock defaults to 3. For manycast service .Cm minsane should be explicitly set to 4, assuming at least that number of servers are available. .Pp If at least .Cm minclock servers are found, the manycast poll interval is immediately set to eight times .Cm maxpoll . If less than .Cm minclock servers are found when the TTL has reached the maximum hops, the manycast poll interval is doubled. For each transmission after that, the poll interval is doubled again until reaching the maximum of eight times .Cm maxpoll . Further transmissions use the same poll interval and TTL values. Note that while all this is going on, each client/server association found is operating normally it the system poll interval. .Pp Administratively scoped multicast boundaries are normally specified by the network router configuration and, in the case of IPv6, the link/site scope prefix. By default, the increment for TTL hops is 32 starting from 31; however, the .Ic ttl configuration command can be used to modify the values to match the scope rules. .Pp It is often useful to narrow the range of acceptable servers which can be found by manycast client associations. Because manycast servers respond only when the client stratum is equal to or greater than the server stratum, primary (stratum 1) servers fill find only primary servers in TTL range, which is probably the most common objective. However, unless configured otherwise, all manycast clients in TTL range will eventually find all primary servers in TTL range, which is probably not the most common objective in large networks. The .Ic tos command can be used to modify this behavior. Servers with stratum below .Cm floor or above .Cm ceiling specified in the .Ic tos command are strongly discouraged during the selection process; however, these servers may be temporally accepted if the number of servers within TTL range is less than .Cm minclock . .Pp The above actions occur for each manycast client message, which repeats at the designated poll interval. However, once the ephemeral client association is mobilized, subsequent manycast server replies are discarded, since that would result in a duplicate association. If during a poll interval the number of client associations falls below .Cm minclock , all manycast client prototype associations are reset to the initial poll interval and TTL hops and operation resumes from the beginning. It is important to avoid frequent manycast client messages, since each one requires all manycast servers in TTL range to respond. The result could well be an implosion, either minor or major, depending on the number of servers in range. The recommended value for .Cm maxpoll is 12 (4,096 s). .Pp It is possible and frequently useful to configure a host as both manycast client and manycast server. A number of hosts configured this way and sharing a common group address will automatically organize themselves in an optimum configuration based on stratum and synchronization distance. For example, consider an NTP subnet of two primary servers and a hundred or more dependent clients. With two exceptions, all servers and clients have identical configuration files including both .Ic multicastclient and .Ic multicastserver commands using, for instance, multicast group address 239.1.1.1. The only exception is that each primary server configuration file must include commands for the primary reference source such as a GPS receiver. .Pp The remaining configuration files for all secondary servers and clients have the same contents, except for the .Ic tos command, which is specific for each stratum level. For stratum 1 and stratum 2 servers, that command is not necessary. For stratum 3 and above servers the .Cm floor value is set to the intended stratum number. Thus, all stratum 3 configuration files are identical, all stratum 4 files are identical and so forth. .Pp Once operations have stabilized in this scenario, the primary servers will find the primary reference source and each other, since they both operate at the same stratum (1), but not with any secondary server or client, since these operate at a higher stratum. The secondary servers will find the servers at the same stratum level. If one of the primary servers loses its GPS receiver, it will continue to operate as a client and other clients will time out the corresponding association and re-associate accordingly. .Pp Some administrators prefer to avoid running .Xr ntpd 1ntpdmdoc continuously and run either .Xr sntp 1sntpmdoc or .Xr ntpd 1ntpdmdoc .Fl q as a cron job. In either case the servers must be configured in advance and the program fails if none are available when the cron job runs. A really slick application of manycast is with .Xr ntpd 1ntpdmdoc .Fl q . The program wakes up, scans the local landscape looking for the usual suspects, selects the best from among the rascals, sets the clock and then departs. Servers do not have to be configured in advance and all clients throughout the network can have the same configuration file. .Ss Manycast Interactions with Autokey Each time a manycast client sends a client mode packet to a multicast group address, all manycast servers in scope generate a reply including the host name and status word. The manycast clients then run the Autokey protocol, which collects and verifies all certificates involved. Following the burst interval all but three survivors are cast off, but the certificates remain in the local cache. It often happens that several complete signing trails from the client to the primary servers are collected in this way. .Pp About once an hour or less often if the poll interval exceeds this, the client regenerates the Autokey key list. This is in general transparent in client/server mode. However, about once per day the server private value used to generate cookies is refreshed along with all manycast client associations. In this case all cryptographic values including certificates is refreshed. If a new certificate has been generated since the last refresh epoch, it will automatically revoke all prior certificates that happen to be in the certificate cache. At the same time, the manycast scheme starts all over from the beginning and the expanding ring shrinks to the minimum and increments from there while collecting all servers in scope. .Ss Broadcast Options .Bl -tag -width indent .It Xo Ic tos .Oo .Cm bcpollbstep Ar gate .Oc .Xc This command provides a way to delay, by the specified number of broadcast poll intervals, believing backward time steps from a broadcast server. Broadcast time networks are expected to be trusted. In the event a broadcast server's time is stepped backwards, there is clear benefit to having the clients notice this change as soon as possible. Attacks such as replay attacks can happen, however, and even though there are a number of protections built in to broadcast mode, attempts to perform a replay attack are possible. This value defaults to 0, but can be changed to any number of poll intervals between 0 and 4. .El .Ss Manycast Options .Bl -tag -width indent .It Xo Ic tos .Oo .Cm ceiling Ar ceiling | .Cm cohort { 0 | 1 } | .Cm floor Ar floor | .Cm minclock Ar minclock | .Cm minsane Ar minsane .Oc .Xc This command affects the clock selection and clustering algorithms. It can be used to select the quality and quantity of peers used to synchronize the system clock and is most useful in manycast mode. The variables operate as follows: .Bl -tag -width indent .It Cm ceiling Ar ceiling Peers with strata above .Cm ceiling will be discarded if there are at least .Cm minclock peers remaining. This value defaults to 15, but can be changed to any number from 1 to 15. .It Cm cohort Bro 0 | 1 Brc This is a binary flag which enables (0) or disables (1) manycast server replies to manycast clients with the same stratum level. This is useful to reduce implosions where large numbers of clients with the same stratum level are present. The default is to enable these replies. .It Cm floor Ar floor Peers with strata below .Cm floor will be discarded if there are at least .Cm minclock peers remaining. This value defaults to 1, but can be changed to any number from 1 to 15. .It Cm minclock Ar minclock The clustering algorithm repeatedly casts out outlier associations until no more than .Cm minclock associations remain. This value defaults to 3, but can be changed to any number from 1 to the number of configured sources. .It Cm minsane Ar minsane This is the minimum number of candidates available to the clock selection algorithm in order to produce one or more truechimers for the clustering algorithm. If fewer than this number are available, the clock is undisciplined and allowed to run free. The default is 1 for legacy purposes. However, according to principles of Byzantine agreement, .Cm minsane should be at least 4 in order to detect and discard a single falseticker. .El .It Cm ttl Ar hop ... This command specifies a list of TTL values in increasing order, up to 8 values can be specified. In manycast mode these values are used in turn in an expanding-ring search. The default is eight multiples of 32 starting at 31. .El .Sh Reference Clock Support The NTP Version 4 daemon supports some three dozen different radio, satellite and modem reference clocks plus a special pseudo-clock used for backup or when no other clock source is available. Detailed descriptions of individual device drivers and options can be found in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . Additional information can be found in the pages linked there, including the .Qq Debugging Hints for Reference Clock Drivers and .Qq How To Write a Reference Clock Driver pages (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . In addition, support for a PPS signal is available as described in the .Qq Pulse-per-second (PPS) Signal Interfacing page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . Many drivers support special line discipline/streams modules which can significantly improve the accuracy using the driver. These are described in the .Qq Line Disciplines and Streams Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Pp A reference clock will generally (though not always) be a radio timecode receiver which is synchronized to a source of standard time such as the services offered by the NRC in Canada and NIST and USNO in the US. The interface between the computer and the timecode receiver is device dependent, but is usually a serial port. A device driver specific to each reference clock must be selected and compiled in the distribution; however, most common radio, satellite and modem clocks are included by default. Note that an attempt to configure a reference clock when the driver has not been compiled or the hardware port has not been appropriately configured results in a scalding remark to the system log file, but is otherwise non hazardous. .Pp For the purposes of configuration, .Xr ntpd 1ntpdmdoc treats reference clocks in a manner analogous to normal NTP peers as much as possible. Reference clocks are identified by a syntactically correct but invalid IP address, in order to distinguish them from normal NTP peers. Reference clock addresses are of the form .Sm off .Li 127.127. Ar t . Ar u , .Sm on where .Ar t is an integer denoting the clock type and .Ar u indicates the unit number in the range 0-3. While it may seem overkill, it is in fact sometimes useful to configure multiple reference clocks of the same type, in which case the unit numbers must be unique. .Pp The .Ic server command is used to configure a reference clock, where the .Ar address argument in that command is the clock address. The .Cm key , .Cm version and .Cm ttl options are not used for reference clock support. The .Cm mode option is added for reference clock support, as described below. The .Cm prefer option can be useful to persuade the server to cherish a reference clock with somewhat more enthusiasm than other reference clocks or peers. Further information on this option can be found in the .Qq Mitigation Rules and the prefer Keyword (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) page. The .Cm minpoll and .Cm maxpoll options have meaning only for selected clock drivers. See the individual clock driver document pages for additional information. .Pp The .Ic fudge command is used to provide additional information for individual clock drivers and normally follows immediately after the .Ic server command. The .Ar address argument specifies the clock address. The .Cm refid and .Cm stratum options can be used to override the defaults for the device. There are two optional device-dependent time offsets and four flags that can be included in the .Ic fudge command as well. .Pp The stratum number of a reference clock is by default zero. Since the .Xr ntpd 1ntpdmdoc daemon adds one to the stratum of each peer, a primary server ordinarily displays an external stratum of one. In order to provide engineered backups, it is often useful to specify the reference clock stratum as greater than zero. The .Cm stratum option is used for this purpose. Also, in cases involving both a reference clock and a pulse-per-second (PPS) discipline signal, it is useful to specify the reference clock identifier as other than the default, depending on the driver. The .Cm refid option is used for this purpose. Except where noted, these options apply to all clock drivers. .Ss Reference Clock Commands .Bl -tag -width indent .It Xo Ic server .Sm off .Li 127.127. Ar t . Ar u .Sm on .Op Cm prefer .Op Cm mode Ar int .Op Cm minpoll Ar int .Op Cm maxpoll Ar int .Xc This command can be used to configure reference clocks in special ways. The options are interpreted as follows: .Bl -tag -width indent .It Cm prefer Marks the reference clock as preferred. All other things being equal, this host will be chosen for synchronization among a set of correctly operating hosts. See the .Qq Mitigation Rules and the prefer Keyword page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) for further information. .It Cm mode Ar int Specifies a mode number which is interpreted in a device-specific fashion. For instance, it selects a dialing protocol in the ACTS driver and a device subtype in the parse drivers. .It Cm minpoll Ar int .It Cm maxpoll Ar int These options specify the minimum and maximum polling interval for reference clock messages, as a power of 2 in seconds For most directly connected reference clocks, both .Cm minpoll and .Cm maxpoll default to 6 (64 s). For modem reference clocks, .Cm minpoll defaults to 10 (17.1 m) and .Cm maxpoll defaults to 14 (4.5 h). The allowable range is 4 (16 s) to 17 (36.4 h) inclusive. .El .It Xo Ic fudge .Sm off .Li 127.127. Ar t . Ar u .Sm on .Op Cm time1 Ar sec .Op Cm time2 Ar sec .Op Cm stratum Ar int .Op Cm refid Ar string .Op Cm mode Ar int .Op Cm flag1 Cm 0 \&| Cm 1 .Op Cm flag2 Cm 0 \&| Cm 1 .Op Cm flag3 Cm 0 \&| Cm 1 .Op Cm flag4 Cm 0 \&| Cm 1 .Xc This command can be used to configure reference clocks in special ways. It must immediately follow the .Ic server command which configures the driver. Note that the same capability is possible at run time using the .Xr ntpdc 1ntpdcmdoc program. The options are interpreted as follows: .Bl -tag -width indent .It Cm time1 Ar sec Specifies a constant to be added to the time offset produced by the driver, a fixed-point decimal number in seconds. This is used as a calibration constant to adjust the nominal time offset of a particular clock to agree with an external standard, such as a precision PPS signal. It also provides a way to correct a systematic error or bias due to serial port or operating system latencies, different cable lengths or receiver internal delay. The specified offset is in addition to the propagation delay provided by other means, such as internal DIPswitches. Where a calibration for an individual system and driver is available, an approximate correction is noted in the driver documentation pages. Note: in order to facilitate calibration when more than one radio clock or PPS signal is supported, a special calibration feature is available. It takes the form of an argument to the .Ic enable command described in .Sx Miscellaneous Options page and operates as described in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .It Cm time2 Ar secs Specifies a fixed-point decimal number in seconds, which is interpreted in a driver-dependent way. See the descriptions of specific drivers in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ). .It Cm stratum Ar int Specifies the stratum number assigned to the driver, an integer between 0 and 15. This number overrides the default stratum number ordinarily assigned by the driver itself, usually zero. .It Cm refid Ar string Specifies an ASCII string of from one to four characters which defines the reference identifier used by the driver. This string overrides the default identifier ordinarily assigned by the driver itself. .It Cm mode Ar int Specifies a mode number which is interpreted in a device-specific fashion. For instance, it selects a dialing protocol in the ACTS driver and a device subtype in the parse drivers. .It Cm flag1 Cm 0 \&| Cm 1 .It Cm flag2 Cm 0 \&| Cm 1 .It Cm flag3 Cm 0 \&| Cm 1 .It Cm flag4 Cm 0 \&| Cm 1 These four flags are used for customizing the clock driver. The interpretation of these values, and whether they are used at all, is a function of the particular clock driver. However, by convention .Cm flag4 is used to enable recording monitoring data to the .Cm clockstats file configured with the .Ic filegen command. Further information on the .Ic filegen command can be found in .Sx Monitoring Options . .El .El .Sh Miscellaneous Options .Bl -tag -width indent .It Ic broadcastdelay Ar seconds The broadcast and multicast modes require a special calibration to determine the network delay between the local and remote servers. Ordinarily, this is done automatically by the initial protocol exchanges between the client and server. In some cases, the calibration procedure may fail due to network or server access controls, for example. This command specifies the default delay to be used under these circumstances. Typically (for Ethernet), a number between 0.003 and 0.007 seconds is appropriate. The default when this command is not used is 0.004 seconds. .It Ic driftfile Ar driftfile This command specifies the complete path and name of the file used to record the frequency of the local clock oscillator. This is the same operation as the .Fl f command line option. If the file exists, it is read at startup in order to set the initial frequency and then updated once per hour with the current frequency computed by the daemon. If the file name is specified, but the file itself does not exist, the starts with an initial frequency of zero and creates the file when writing it for the first time. If this command is not given, the daemon will always start with an initial frequency of zero. .Pp The file format consists of a single line containing a single floating point number, which records the frequency offset measured in parts-per-million (PPM). The file is updated by first writing the current drift value into a temporary file and then renaming this file to replace the old version. This implies that .Xr ntpd 1ntpdmdoc must have write permission for the directory the drift file is located in, and that file system links, symbolic or otherwise, should be avoided. .It Ic dscp Ar value This option specifies the Differentiated Services Control Point (DSCP) value, a 6-bit code. The default value is 46, signifying Expedited Forwarding. .It Xo Ic enable .Oo .Cm auth | Cm bclient | .Cm calibrate | Cm kernel | .Cm mode7 | Cm monitor | .Cm ntp | Cm stats | .Cm peer_clear_digest_early | .Cm unpeer_crypto_early | Cm unpeer_crypto_nak_early | Cm unpeer_digest_early .Oc .Xc .It Xo Ic disable .Oo .Cm auth | Cm bclient | .Cm calibrate | Cm kernel | .Cm mode7 | Cm monitor | .Cm ntp | Cm stats | .Cm peer_clear_digest_early | .Cm unpeer_crypto_early | Cm unpeer_crypto_nak_early | Cm unpeer_digest_early .Oc .Xc Provides a way to enable or disable various server options. Flags not mentioned are unaffected. Note that all of these flags can be controlled remotely using the .Xr ntpdc 1ntpdcmdoc utility program. .Bl -tag -width indent .It Cm auth Enables the server to synchronize with unconfigured peers only if the peer has been correctly authenticated using either public key or private key cryptography. The default for this flag is .Ic enable . .It Cm bclient Enables the server to listen for a message from a broadcast or multicast server, as in the .Ic multicastclient command with default address. The default for this flag is .Ic disable . .It Cm calibrate Enables the calibrate feature for reference clocks. The default for this flag is .Ic disable . .It Cm kernel Enables the kernel time discipline, if available. The default for this flag is .Ic enable if support is available, otherwise .Ic disable . .It Cm mode7 Enables processing of NTP mode 7 implementation-specific requests which are used by the deprecated .Xr ntpdc 1ntpdcmdoc program. The default for this flag is disable. This flag is excluded from runtime configuration using .Xr ntpq 1ntpqmdoc . The .Xr ntpq 1ntpqmdoc program provides the same capabilities as .Xr ntpdc 1ntpdcmdoc using standard mode 6 requests. .It Cm monitor Enables the monitoring facility. See the .Xr ntpdc 1ntpdcmdoc program and the .Ic monlist command or further information. The default for this flag is .Ic enable . .It Cm ntp Enables time and frequency discipline. In effect, this switch opens and closes the feedback loop, which is useful for testing. The default for this flag is .Ic enable . .It Cm peer_clear_digest_early By default, if .Xr ntpd 1ntpdmdoc is using autokey and it receives a crypto-NAK packet that passes the duplicate packet and origin timestamp checks the peer variables are immediately cleared. While this is generally a feature as it allows for quick recovery if a server key has changed, a properly forged and appropriately delivered crypto-NAK packet can be used in a DoS attack. If you have active noticable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm stats Enables the statistics facility. See the .Sx Monitoring Options section for further information. The default for this flag is .Ic disable . .It Cm unpeer_crypto_early By default, if .Xr ntpd 1ntpdmdoc receives an autokey packet that fails TEST9, a crypto failure, the association is immediately cleared. This is almost certainly a feature, but if, in spite of the current recommendation of not using autokey, you are .B still using autokey .B and you are seeing this sort of DoS attack disabling this flag will delay tearing down the association until the reachability counter becomes zero. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm unpeer_crypto_nak_early By default, if .Xr ntpd 1ntpdmdoc receives a crypto-NAK packet that passes the duplicate packet and origin timestamp checks the association is immediately cleared. While this is generally a feature as it allows for quick recovery if a server key has changed, a properly forged and appropriately delivered crypto-NAK packet can be used in a DoS attack. If you have active noticable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm unpeer_digest_early By default, if .Xr ntpd 1ntpdmdoc receives what should be an authenticated packet that passes other packet sanity checks but contains an invalid digest the association is immediately cleared. While this is generally a feature as it allows for quick recovery, if this type of packet is carefully forged and sent during an appropriate window it can be used for a DoS attack. If you have active noticable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .El .It Ic includefile Ar includefile This command allows additional configuration commands to be included from a separate file. Include files may be nested to a depth of five; upon reaching the end of any include file, command processing resumes in the previous configuration file. This option is useful for sites that run .Xr ntpd 1ntpdmdoc on multiple hosts, with (mostly) common options (e.g., a restriction list). .It Xo Ic interface .Oo .Cm listen | Cm ignore | Cm drop .Oc .Oo .Cm all | Cm ipv4 | Cm ipv6 | Cm wildcard .Ar name | Ar address .Oo Cm / Ar prefixlen .Oc .Oc .Xc The .Cm interface directive controls which network addresses .Xr ntpd 1ntpdmdoc opens, and whether input is dropped without processing. The first parameter determines the action for addresses which match the second parameter. The second parameter specifies a class of addresses, or a specific interface name, or an address. In the address case, .Ar prefixlen determines how many bits must match for this rule to apply. .Cm ignore prevents opening matching addresses, .Cm drop causes .Xr ntpd 1ntpdmdoc to open the address and drop all received packets without examination. Multiple .Cm interface directives can be used. The last rule which matches a particular address determines the action for it. .Cm interface directives are disabled if any .Fl I , .Fl -interface , .Fl L , or .Fl -novirtualips command-line options are specified in the configuration file, all available network addresses are opened. The .Cm nic directive is an alias for .Cm interface . .It Ic leapfile Ar leapfile This command loads the IERS leapseconds file and initializes the leapsecond values for the next leapsecond event, leapfile expiration time, and TAI offset. The file can be obtained directly from the IERS at .Li https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list or .Li ftp://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list . The .Cm leapfile is scanned when .Xr ntpd 1ntpdmdoc processes the .Cm leapfile directive or when .Cm ntpd detects that the .Ar leapfile has changed. .Cm ntpd checks once a day to see if the .Ar leapfile has changed. The .Xr update-leap 1update_leapmdoc script can be run to see if the .Ar leapfile should be updated. .It Ic leapsmearinterval Ar seconds This EXPERIMENTAL option is only available if .Xr ntpd 1ntpdmdoc was built with the .Cm --enable-leap-smear option to the .Cm configure script. It specifies the interval over which a leap second correction will be applied. Recommended values for this option are between 7200 (2 hours) and 86400 (24 hours). .Sy DO NOT USE THIS OPTION ON PUBLIC-ACCESS SERVERS! See http://bugs.ntp.org/2855 for more information. .It Ic logconfig Ar configkeyword This command controls the amount and type of output written to the system .Xr syslog 3 facility or the alternate .Ic logfile log file. By default, all output is turned on. All .Ar configkeyword keywords can be prefixed with .Ql = , .Ql + and .Ql - , where .Ql = sets the .Xr syslog 3 priority mask, .Ql + adds and .Ql - removes messages. .Xr syslog 3 messages can be controlled in four classes .Po .Cm clock , .Cm peer , .Cm sys and .Cm sync .Pc . Within these classes four types of messages can be controlled: informational messages .Po .Cm info .Pc , event messages .Po .Cm events .Pc , statistics messages .Po .Cm statistics .Pc and status messages .Po .Cm status .Pc . .Pp Configuration keywords are formed by concatenating the message class with the event class. The .Cm all prefix can be used instead of a message class. A message class may also be followed by the .Cm all keyword to enable/disable all messages of the respective message class. Thus, a minimal log configuration could look like this: .Bd -literal logconfig =syncstatus +sysevents .Ed .Pp This would just list the synchronizations state of .Xr ntpd 1ntpdmdoc and the major system events. For a simple reference server, the following minimum message configuration could be useful: .Bd -literal logconfig =syncall +clockall .Ed .Pp This configuration will list all clock information and synchronization information. All other events and messages about peers, system events and so on is suppressed. .It Ic logfile Ar logfile This command specifies the location of an alternate log file to be used instead of the default system .Xr syslog 3 facility. This is the same operation as the .Fl l command line option. .It Xo Ic mru .Oo .Cm maxdepth Ar count | Cm maxmem Ar kilobytes | .Cm mindepth Ar count | Cm maxage Ar seconds | .Cm initialloc Ar count | Cm initmem Ar kilobytes | .Cm incalloc Ar count | Cm incmem Ar kilobytes .Oc .Xc Controls size limite of the monitoring facility's Most Recently Used (MRU) list of client addresses, which is also used by the rate control facility. .Bl -tag -width indent .It Ic maxdepth Ar count .It Ic maxmem Ar kilobytes Equivalent upper limits on the size of the MRU list, in terms of entries or kilobytes. The acutal limit will be up to .Cm incalloc entries or .Cm incmem kilobytes larger. As with all of the .Cm mru options offered in units of entries or kilobytes, if both .Cm maxdepth and .Cm maxmem are used, the last one used controls. The default is 1024 kilobytes. .It Cm mindepth Ar count Lower limit on the MRU list size. When the MRU list has fewer than .Cm mindepth entries, existing entries are never removed to make room for newer ones, regardless of their age. The default is 600 entries. .It Cm maxage Ar seconds Once the MRU list has .Cm mindepth entries and an additional client is to ba added to the list, if the oldest entry was updated more than .Cm maxage seconds ago, that entry is removed and its storage is reused. If the oldest entry was updated more recently the MRU list is grown, subject to .Cm maxdepth / moxmem . The default is 64 seconds. .It Cm initalloc Ar count .It Cm initmem Ar kilobytes Initial memory allocation at the time the monitoringfacility is first enabled, in terms of the number of entries or kilobytes. The default is 4 kilobytes. .It Cm incalloc Ar count .It Cm incmem Ar kilobytes Size of additional memory allocations when growing the MRU list, in entries or kilobytes. The default is 4 kilobytes. .El .It Ic nonvolatile Ar threshold Specify the .Ar threshold delta in seconds before an hourly change to the .Cm driftfile (frequency file) will be written, with a default value of 1e-7 (0.1 PPM). The frequency file is inspected each hour. If the difference between the current frequency and the last value written exceeds the threshold, the file is written and the .Cm threshold becomes the new threshold value. If the threshold is not exceeeded, it is reduced by half. This is intended to reduce the number of file writes for embedded systems with nonvolatile memory. .It Ic phone Ar dial ... This command is used in conjunction with the ACTS modem driver (type 18) or the JJY driver (type 40, mode 100 - 180). For the ACTS modem driver (type 18), the arguments consist of a maximum of 10 telephone numbers used to dial USNO, NIST, or European time service. For the JJY driver (type 40 mode 100 - 180), the argument is one telephone number used to dial the telephone JJY service. The Hayes command ATDT is normally prepended to the number. The number can contain other modem control codes as well. .It Xo Cm pollskewlist .Oo .Ar poll .Ar early late .Oc .Ar ... .Oo .Cm default .Ar early late .Oc .Xc Enable skewing of our poll requests to our servers. .Ar poll is a number between 3 and 17 inclusive, identifying a specific poll interval. A poll interval is 2^n seconds in duration, so a poll value of 3 corresponds to 8 seconds and a poll interval of 17 corresponds to 131,072 seconds, or about a day and a half. The next two numbers must be between 0 and one-half of the poll interval, inclusive. Ar early specifies how early the poll may start, while Ar late specifies how late the poll may be delayed. With no arguments, internally specified default values are chosen. .It Xo Ic reset .Oo .Ic allpeers .Oc .Oo .Ic auth .Oc .Oo .Ic ctl .Oc .Oo .Ic io .Oc .Oo .Ic mem .Oc .Oo .Ic sys .Oc .Oo .Ic timer .Oc .Xc Reset one or more groups of counters maintained by .Cm ntpd and exposed by .Cm ntpq and .Cm ntpdc . .It Xo Ic rlimit .Oo .Cm memlock Ar Nmegabytes | .Cm stacksize Ar N4kPages .Cm filenum Ar Nfiledescriptors .Oc .Xc .Bl -tag -width indent .It Cm memlock Ar Nmegabytes Specify the number of megabytes of memory that should be allocated and locked. Probably only available under Linux, this option may be useful when dropping root (the .Fl i option). The default is 32 megabytes on non-Linux machines, and -1 under Linux. -1 means "do not lock the process into memory". 0 means "lock whatever memory the process wants into memory". .It Cm stacksize Ar N4kPages Specifies the maximum size of the process stack on systems with the .Fn mlockall function. Defaults to 50 4k pages (200 4k pages in OpenBSD). .It Cm filenum Ar Nfiledescriptors Specifies the maximum number of file descriptors ntpd may have open at once. Defaults to the system default. .El .It Ic saveconfigdir Ar directory_path Specify the directory in which to write configuration snapshots requested with .Cm ntpq 's .Cm saveconfig command. If .Cm saveconfigdir does not appear in the configuration file, .Cm saveconfig requests are rejected by .Cm ntpd . .It Ic saveconfig Ar filename Write the current configuration, including any runtime modifications given with .Cm :config or .Cm config-from-file to the .Cm ntpd host's .Ar filename in the .Cm saveconfigdir . This command will be rejected unless the .Cm saveconfigdir directive appears in .Cm ntpd 's configuration file. .Ar filename can use .Xr strftime 3 format directives to substitute the current date and time, for example, .Cm saveconfig\ ntp-%Y%m%d-%H%M%S.conf . The filename used is stored in the system variable .Cm savedconfig . Authentication is required. .It Ic setvar Ar variable Op Cm default This command adds an additional system variable. These variables can be used to distribute additional information such as the access policy. If the variable of the form .Sm off .Va name = Ar value .Sm on is followed by the .Cm default keyword, the variable will be listed as part of the default system variables .Po .Xr ntpq 1ntpqmdoc .Ic rv command .Pc ) . These additional variables serve informational purposes only. They are not related to the protocol other that they can be listed. The known protocol variables will always override any variables defined via the .Ic setvar mechanism. There are three special variables that contain the names of all variable of the same group. The .Va sys_var_list holds the names of all system variables. The .Va peer_var_list holds the names of all peer variables and the .Va clock_var_list holds the names of the reference clock variables. .It Cm sysinfo Display operational summary. .It Cm sysstats Show statistics counters maintained in the protocol module. .It Xo Ic tinker .Oo .Cm allan Ar allan | .Cm dispersion Ar dispersion | .Cm freq Ar freq | .Cm huffpuff Ar huffpuff | .Cm panic Ar panic | .Cm step Ar step | .Cm stepback Ar stepback | .Cm stepfwd Ar stepfwd | .Cm stepout Ar stepout .Oc .Xc This command can be used to alter several system variables in very exceptional circumstances. It should occur in the configuration file before any other configuration options. The default values of these variables have been carefully optimized for a wide range of network speeds and reliability expectations. In general, they interact in intricate ways that are hard to predict and some combinations can result in some very nasty behavior. Very rarely is it necessary to change the default values; but, some folks cannot resist twisting the knobs anyway and this command is for them. Emphasis added: twisters are on their own and can expect no help from the support group. .Pp The variables operate as follows: .Bl -tag -width indent .It Cm allan Ar allan The argument becomes the new value for the minimum Allan intercept, which is a parameter of the PLL/FLL clock discipline algorithm. The value in log2 seconds defaults to 7 (1024 s), which is also the lower limit. .It Cm dispersion Ar dispersion The argument becomes the new value for the dispersion increase rate, normally .000015 s/s. .It Cm freq Ar freq The argument becomes the initial value of the frequency offset in parts-per-million. This overrides the value in the frequency file, if present, and avoids the initial training state if it is not. .It Cm huffpuff Ar huffpuff The argument becomes the new value for the experimental huff-n'-puff filter span, which determines the most recent interval the algorithm will search for a minimum delay. The lower limit is 900 s (15 m), but a more reasonable value is 7200 (2 hours). There is no default, since the filter is not enabled unless this command is given. .It Cm panic Ar panic The argument is the panic threshold, normally 1000 s. If set to zero, the panic sanity check is disabled and a clock offset of any value will be accepted. .It Cm step Ar step The argument is the step threshold, which by default is 0.128 s. It can be set to any positive number in seconds. If set to zero, step adjustments will never occur. Note: The kernel time discipline is disabled if the step threshold is set to zero or greater than the default. .It Cm stepback Ar stepback The argument is the step threshold for the backward direction, which by default is 0.128 s. It can be set to any positive number in seconds. If both the forward and backward step thresholds are set to zero, step adjustments will never occur. Note: The kernel time discipline is disabled if each direction of step threshold are either set to zero or greater than .5 second. .It Cm stepfwd Ar stepfwd As for stepback, but for the forward direction. .It Cm stepout Ar stepout The argument is the stepout timeout, which by default is 900 s. It can be set to any positive number in seconds. If set to zero, the stepout pulses will not be suppressed. .El .It Cm writevar Ar assocID\ name = value [,...] Write (create or update) the specified variables. If the .Cm assocID is zero, the variablea re from the system variables name space, otherwise they are from the peer variables name space. The .Cm assocID is required, as the same name can occur in both name spaces. .It Xo Ic trap Ar host_address .Op Cm port Ar port_number .Op Cm interface Ar interface_address .Xc This command configures a trap receiver at the given host address and port number for sending messages with the specified local interface address. If the port number is unspecified, a value of 18447 is used. If the interface address is not specified, the message is sent with a source address of the local interface the message is sent through. Note that on a multihomed host the interface used may vary from time to time with routing changes. .It Cm ttl Ar hop ... This command specifies a list of TTL values in increasing order. Up to 8 values can be specified. In .Cm manycast mode these values are used in-turn in an expanding-ring search. The default is eight multiples of 32 starting at 31. .Pp The trap receiver will generally log event messages and other information from the server in a log file. While such monitor programs may also request their own trap dynamically, configuring a trap receiver will ensure that no messages are lost when the server is started. .It Cm hop Ar ... This command specifies a list of TTL values in increasing order, up to 8 values can be specified. In manycast mode these values are used in turn in an expanding-ring search. The default is eight multiples of 32 starting at 31. .El _END_PROG_MDOC_DESCRIP; }; doc-section = { ds-type = 'FILES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_FILES .Bl -tag -width /etc/ntp.drift -compact .It Pa /etc/ntp.conf the default name of the configuration file .It Pa ntp.keys private MD5 keys .It Pa ntpkey RSA private key .It Pa ntpkey_ Ns Ar host RSA public key .It Pa ntp_dh Diffie-Hellman agreement parameters .El _END_MDOC_FILES; }; doc-section = { ds-type = 'SEE ALSO'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_SEE_ALSO .Xr ntpd 1ntpdmdoc , .Xr ntpdc 1ntpdcmdoc , .Xr ntpq 1ntpqmdoc .Pp In addition to the manual pages provided, comprehensive documentation is available on the world wide web at .Li http://www.ntp.org/ . A snapshot of this documentation is available in HTML format in .Pa /usr/share/doc/ntp . .Rs .%A David L. Mills .%T Network Time Protocol (Version 4) .%O RFC5905 .Re _END_MDOC_SEE_ALSO; }; doc-section = { ds-type = 'BUGS'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_BUGS The syntax checking is not picky; some combinations of ridiculous and even hilarious options and modes may not be detected. .Pp The .Pa ntpkey_ Ns Ar host files are really digital certificates. These should be obtained via secure directory services when they become universally available. _END_MDOC_BUGS; }; doc-section = { ds-type = 'NOTES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_NOTES This document was derived from FreeBSD. _END_MDOC_NOTES; }; diff --git a/contrib/ntp/ntpd/ntp.keys.def b/contrib/ntp/ntpd/ntp.keys.def index e73ce4d06a1b..b0c9717e5906 100644 --- a/contrib/ntp/ntpd/ntp.keys.def +++ b/contrib/ntp/ntpd/ntp.keys.def @@ -1,168 +1,168 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include copyright.def #include version.def // We want the synopsis to be "/etc/ntp.keys" but we need the prog-name // to be ntp.keys - the latter is also how autogen produces the output // file name. prog-name = "ntp.keys"; file-path = "/etc/ntp.keys"; -prog-title = "NTP symmetric key file format"; +prog-title = "Network Time Protocol symmetric key format"; /* explain: Additional information whenever the usage routine is invoked */ explain = <<- _END_EXPLAIN _END_EXPLAIN; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP This document describes the format of an NTP symmetric key file. For a description of the use of this type of file, see the .Qq Authentication Support section of the .Xr ntp.conf 5 page. .Pp .Xr ntpd 8 reads its keys from a file specified using the .Fl k command line option or the .Ic keys statement in the configuration file. While key number 0 is fixed by the NTP standard (as 56 zero bits) and may not be changed, one or more keys numbered between 1 and 65535 may be arbitrarily set in the keys file. .Pp The key file uses the same comment conventions as the configuration file. Key entries use a fixed format of the form .Pp .D1 Ar keyno type key opt_IP_list .Pp where .Ar keyno is a positive integer (between 1 and 65535), .Ar type is the message digest algorithm, .Ar key is the key itself, and .Ar opt_IP_list is an optional comma-separated list of IPs where the .Ar keyno should be trusted. that are allowed to serve time. Each IP in .Ar opt_IP_list may contain an optional .Cm /subnetbits specification which identifies the number of bits for the desired subnet of trust. If .Ar opt_IP_list is empty, any properly-authenticated message will be accepted. .Pp The .Ar key may be given in a format controlled by the .Ar type field. The .Ar type .Li MD5 is always supported. If .Li ntpd was built with the OpenSSL library then any digest library supported by that library may be specified. However, if compliance with FIPS 140-2 is required the .Ar type must be either .Li SHA or .Li SHA1 . .Pp What follows are some key types, and corresponding formats: .Pp .Bl -tag -width RMD160 -compact .It Li MD5 The key is 1 to 16 printable characters terminated by an EOL, whitespace, or a .Li # (which is the "start of comment" character). .Pp .It Li SHA .It Li SHA1 .It Li RMD160 The key is a hex-encoded ASCII string of 40 characters, which is truncated as necessary. .El .Pp Note that the keys used by the .Xr ntpq 8 and .Xr ntpdc 8 programs are checked against passwords requested by the programs and entered by hand, so it is generally appropriate to specify these keys in ASCII format. _END_PROG_MDOC_DESCRIP; }; doc-section = { ds-type = 'FILES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_FILES .Bl -tag -width /etc/ntp.keys -compact .It Pa /etc/ntp.keys the default name of the configuration file .El _END_MDOC_FILES; }; doc-section = { ds-type = 'SEE ALSO'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_SEE_ALSO .Xr ntp.conf 5 , .Xr ntpd 1ntpdmdoc , .Xr ntpdate 1ntpdatemdoc , .Xr ntpdc 1ntpdcmdoc , .Xr sntp 1sntpmdoc _END_MDOC_SEE_ALSO; }; /* doc-section = { ds-type = 'BUGS'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_BUGS .Xr ntpd 8 has gotten rather fat. While not huge, it has gotten larger than might be desirable for an elevated-priority daemon running on a workstation, particularly since many of the fancy features which consume the space were designed more with a busy primary server, rather than a high stratum workstation, in mind. _END_MDOC_BUGS; }; */ doc-section = { ds-type = 'NOTES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_NOTES This document was derived from FreeBSD. _END_MDOC_NOTES; }; diff --git a/contrib/ntp/ntpd/ntpd-opts.def b/contrib/ntp/ntpd/ntpd-opts.def index 00d35115dc43..6d4952a637c2 100644 --- a/contrib/ntp/ntpd/ntpd-opts.def +++ b/contrib/ntp/ntpd/ntpd-opts.def @@ -1,615 +1,615 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include copyright.def prog-name = "ntpd"; -prog-title = "NTP daemon program"; +prog-title = "set clock via Network Time Protocol daemon"; argument = "[ ... ]"; #include ntpdbase-opts.def /* explain: Additional information whenever the usage routine is invoked */ explain = <<- _END_EXPLAIN _END_EXPLAIN; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP The .Nm utility is an operating system daemon which sets and maintains the system time of day in synchronism with Internet standard time servers. It is a complete implementation of the Network Time Protocol (NTP) version 4, as defined by RFC-5905, but also retains compatibility with version 3, as defined by RFC-1305, and versions 1 and 2, as defined by RFC-1059 and RFC-1119, respectively. .Pp The .Nm utility does most computations in 64-bit floating point arithmetic and does relatively clumsy 64-bit fixed point operations only when necessary to preserve the ultimate precision, about 232 picoseconds. While the ultimate precision is not achievable with ordinary workstations and networks of today, it may be required with future gigahertz CPU clocks and gigabit LANs. .Pp Ordinarily, .Nm reads the .Xr ntp.conf 5 configuration file at startup time in order to determine the synchronization sources and operating modes. It is also possible to specify a working, although limited, configuration entirely on the command line, obviating the need for a configuration file. This may be particularly useful when the local host is to be configured as a broadcast/multicast client, with all peers being determined by listening to broadcasts at run time. .Pp If NetInfo support is built into .Nm , then .Nm will attempt to read its configuration from the NetInfo if the default .Xr ntp.conf 5 file cannot be read and no file is specified by the .Fl c option. .Pp Various internal .Nm variables can be displayed and configuration options altered while the .Nm is running using the .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc utility programs. .Pp When .Nm starts it looks at the value of .Xr umask 2 , and if zero .Nm will set the .Xr umask 2 to 022. _END_PROG_MDOC_DESCRIP; }; doc-section = { ds-type = 'USAGE'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_USAGE .Ss "How NTP Operates" The .Nm utility operates by exchanging messages with one or more configured servers over a range of designated poll intervals. When started, whether for the first or subsequent times, the program requires several exchanges from the majority of these servers so the signal processing and mitigation algorithms can accumulate and groom the data and set the clock. In order to protect the network from bursts, the initial poll interval for each server is delayed an interval randomized over a few seconds. At the default initial poll interval of 64s, several minutes can elapse before the clock is set. This initial delay to set the clock can be safely and dramatically reduced using the .Cm iburst keyword with the .Ic server configuration command, as described in .Xr ntp.conf 5 . .Pp Most operating systems and hardware of today incorporate a time-of-year (TOY) chip to maintain the time during periods when the power is off. When the machine is booted, the chip is used to initialize the operating system time. After the machine has synchronized to a NTP server, the operating system corrects the chip from time to time. In the default case, if .Nm detects that the time on the host is more than 1000s from the server time, .Nm assumes something must be terribly wrong and the only reliable action is for the operator to intervene and set the clock by hand. (Reasons for this include there is no TOY chip, or its battery is dead, or that the TOY chip is just of poor quality.) This causes .Nm to exit with a panic message to the system log. The .Fl g option overrides this check and the clock will be set to the server time regardless of the chip time (up to 68 years in the past or future \(em this is a limitation of the NTPv4 protocol). However, and to protect against broken hardware, such as when the CMOS battery fails or the clock counter becomes defective, once the clock has been set an error greater than 1000s will cause .Nm to exit anyway. .Pp Under ordinary conditions, .Nm adjusts the clock in small steps so that the timescale is effectively continuous and without discontinuities. Under conditions of extreme network congestion, the roundtrip delay jitter can exceed three seconds and the synchronization distance, which is equal to one-half the roundtrip delay plus error budget terms, can become very large. The .Nm algorithms discard sample offsets exceeding 128 ms, unless the interval during which no sample offset is less than 128 ms exceeds 900s. The first sample after that, no matter what the offset, steps the clock to the indicated time. In practice this reduces the false alarm rate where the clock is stepped in error to a vanishingly low incidence. .Pp As the result of this behavior, once the clock has been set it very rarely strays more than 128 ms even under extreme cases of network path congestion and jitter. Sometimes, in particular when .Nm is first started without a valid drift file on a system with a large intrinsic drift the error might grow to exceed 128 ms, which would cause the clock to be set backwards if the local clock time is more than 128 s in the future relative to the server. In some applications, this behavior may be unacceptable. There are several solutions, however. If the .Fl x option is included on the command line, the clock will never be stepped and only slew corrections will be used. But this choice comes with a cost that should be carefully explored before deciding to use the .Fl x option. The maximum slew rate possible is limited to 500 parts-per-million (PPM) as a consequence of the correctness principles on which the NTP protocol and algorithm design are based. As a result, the local clock can take a long time to converge to an acceptable offset, about 2,000 s for each second the clock is outside the acceptable range. During this interval the local clock will not be consistent with any other network clock and the system cannot be used for distributed applications that require correctly synchronized network time. .Pp In spite of the above precautions, sometimes when large frequency errors are present the resulting time offsets stray outside the 128-ms range and an eventual step or slew time correction is required. If following such a correction the frequency error is so large that the first sample is outside the acceptable range, .Nm enters the same state as when the .Pa ntp.drift file is not present. The intent of this behavior is to quickly correct the frequency and restore operation to the normal tracking mode. In the most extreme cases (the host .Cm time.ien.it comes to mind), there may be occasional step/slew corrections and subsequent frequency corrections. It helps in these cases to use the .Cm burst keyword when configuring the server, but ONLY when you have permission to do so from the owner of the target host. .Pp Finally, in the past many startup scripts would run .Xr ntpdate 1ntpdatemdoc or .Xr sntp 1sntpmdoc to get the system clock close to correct before starting .Xr ntpd 1ntpdmdoc , but this was never more than a mediocre hack and is no longer needed. If you are following the instructions in .Sx "Starting NTP (Best Current Practice)" and you still need to set the system time before starting .Nm , please open a bug report and document what is going on, and then look at using .Xr sntp 1sntpmdoc if you really need to set the clock before starting .Nm . .Pp There is a way to start .Xr ntpd 1ntpdmdoc that often addresses all of the problems mentioned above. .Ss "Starting NTP (Best Current Practice)" First, use the .Cm iburst option on your .Cm server entries. .Pp If you can also keep a good .Pa ntp.drift file then .Xr ntpd 1ntpdmdoc will effectively "warm-start" and your system's clock will be stable in under 11 seconds' time. .Pp As soon as possible in the startup sequence, start .Xr ntpd 1ntpdmdoc with at least the .Fl g and perhaps the .Fl N options. Then, start the rest of your "normal" processes. This will give .Xr ntpd 1ntpdmdoc as much time as possible to get the system's clock synchronized and stable. .Pp Finally, if you have processes like .Cm dovecot or database servers that require monotonically-increasing time, run .Xr ntp-wait 1ntp-waitmdoc as late as possible in the boot sequence (perhaps with the .Fl v flag) and after .Xr ntp-wait 1ntp-waitmdoc exits successfully it is as safe as it will ever be to start any process that require stable time. .Ss "Frequency Discipline" The .Nm behavior at startup depends on whether the frequency file, usually .Pa ntp.drift , exists. This file contains the latest estimate of clock frequency error. When the .Nm is started and the file does not exist, the .Nm enters a special mode designed to quickly adapt to the particular system clock oscillator time and frequency error. This takes approximately 15 minutes, after which the time and frequency are set to nominal values and the .Nm enters normal mode, where the time and frequency are continuously tracked relative to the server. After one hour the frequency file is created and the current frequency offset written to it. When the .Nm is started and the file does exist, the .Nm frequency is initialized from the file and enters normal mode immediately. After that the current frequency offset is written to the file at hourly intervals. .Ss "Operating Modes" The .Nm utility can operate in any of several modes, including symmetric active/passive, client/server broadcast/multicast and manycast, as described in the .Qq Association Management page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . It normally operates continuously while monitoring for small changes in frequency and trimming the clock for the ultimate precision. However, it can operate in a one-time mode where the time is set from an external server and frequency is set from a previously recorded frequency file. A broadcast/multicast or manycast client can discover remote servers, compute server-client propagation delay correction factors and configure itself automatically. This makes it possible to deploy a fleet of workstations without specifying configuration details specific to the local environment. .Pp By default, .Nm runs in continuous mode where each of possibly several external servers is polled at intervals determined by an intricate state machine. The state machine measures the incidental roundtrip delay jitter and oscillator frequency wander and determines the best poll interval using a heuristic algorithm. Ordinarily, and in most operating environments, the state machine will start with 64s intervals and eventually increase in steps to 1024s. A small amount of random variation is introduced in order to avoid bunching at the servers. In addition, should a server become unreachable for some time, the poll interval is increased in steps to 1024s in order to reduce network overhead. .Pp In some cases it may not be practical for .Nm to run continuously. A common workaround has been to run the .Xr ntpdate 1ntpdatemdoc or .Xr sntp 1sntpmdoc programs from a .Xr cron 8 job at designated times. However, these programs do not have the crafted signal processing, error checking or mitigation algorithms of .Nm . The .Fl q option is intended for this purpose. Setting this option will cause .Nm to exit just after setting the clock for the first time. The procedure for initially setting the clock is the same as in continuous mode; most applications will probably want to specify the .Cm iburst keyword with the .Ic server configuration command. With this keyword a volley of messages are exchanged to groom the data and the clock is set in about 10 s. If nothing is heard after a couple of minutes, the daemon times out and exits. After a suitable period of mourning, the .Xr ntpdate 1ntpdatemdoc program will be retired. .Pp When kernel support is available to discipline the clock frequency, which is the case for stock Solaris, Tru64, Linux and .Fx , a useful feature is available to discipline the clock frequency. First, .Nm is run in continuous mode with selected servers in order to measure and record the intrinsic clock frequency offset in the frequency file. It may take some hours for the frequency and offset to settle down. Then the .Nm is stopped and run in one-time mode as required. At each startup, the frequency is read from the file and initializes the kernel frequency. .Ss "Poll Interval Control" This version of NTP includes an intricate state machine to reduce the network load while maintaining a quality of synchronization consistent with the observed jitter and wander. There are a number of ways to tailor the operation in order enhance accuracy by reducing the interval or to reduce network overhead by increasing it. However, the user is advised to carefully consider the consequences of changing the poll adjustment range from the default minimum of 64 s to the default maximum of 1,024 s. The default minimum can be changed with the .Ic tinker .Cm minpoll command to a value not less than 16 s. This value is used for all configured associations, unless overridden by the .Cm minpoll option on the configuration command. Note that most device drivers will not operate properly if the poll interval is less than 64 s and that the broadcast server and manycast client associations will also use the default, unless overridden. .Pp In some cases involving dial up or toll services, it may be useful to increase the minimum interval to a few tens of minutes and maximum interval to a day or so. Under normal operation conditions, once the clock discipline loop has stabilized the interval will be increased in steps from the minimum to the maximum. However, this assumes the intrinsic clock frequency error is small enough for the discipline loop correct it. The capture range of the loop is 500 PPM at an interval of 64s decreasing by a factor of two for each doubling of interval. At a minimum of 1,024 s, for example, the capture range is only 31 PPM. If the intrinsic error is greater than this, the drift file .Pa ntp.drift will have to be specially tailored to reduce the residual error below this limit. Once this is done, the drift file is automatically updated once per hour and is available to initialize the frequency on subsequent daemon restarts. .Ss "The huff-n'-puff Filter" In scenarios where a considerable amount of data are to be downloaded or uploaded over telephone modems, timekeeping quality can be seriously degraded. This occurs because the differential delays on the two directions of transmission can be quite large. In many cases the apparent time errors are so large as to exceed the step threshold and a step correction can occur during and after the data transfer is in progress. .Pp The huff-n'-puff filter is designed to correct the apparent time offset in these cases. It depends on knowledge of the propagation delay when no other traffic is present. In common scenarios this occurs during other than work hours. The filter maintains a shift register that remembers the minimum delay over the most recent interval measured usually in hours. Under conditions of severe delay, the filter corrects the apparent offset using the sign of the offset and the difference between the apparent delay and minimum delay. The name of the filter reflects the negative (huff) and positive (puff) correction, which depends on the sign of the offset. .Pp The filter is activated by the .Ic tinker command and .Cm huffpuff keyword, as described in .Xr ntp.conf 5 . _END_MDOC_USAGE; }; doc-section = { ds-type = 'FILES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_FILES .Bl -tag -width /etc/ntp.drift -compact .It Pa /etc/ntp.conf the default name of the configuration file .It Pa /etc/ntp.drift the default name of the drift file .It Pa /etc/ntp.keys the default name of the key file .El _END_MDOC_FILES; }; doc-section = { ds-type = 'SEE ALSO'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_SEE_ALSO .Xr ntp.conf 5 , .Xr ntpdate 1ntpdatemdoc , .Xr ntpdc 1ntpdcmdoc , .Xr ntpq 1ntpqmdoc , .Xr sntp 1sntpmdoc .Pp In addition to the manual pages provided, comprehensive documentation is available on the world wide web at .Li http://www.ntp.org/ . A snapshot of this documentation is available in HTML format in .Pa /usr/share/doc/ntp . .Rs .%A David L. Mills .%T Network Time Protocol (Version 1) .%O RFC1059 .Re .Rs .%A David L. Mills .%T Network Time Protocol (Version 2) .%O RFC1119 .Re .Rs .%A David L. Mills .%T Network Time Protocol (Version 3) .%O RFC1305 .Re .Rs .%A David L. Mills .%A J. Martin, Ed. .%A J. Burbank .%A W. Kasch .%T Network Time Protocol Version 4: Protocol and Algorithms Specification .%O RFC5905 .Re .Rs .%A David L. Mills .%A B. Haberman, Ed. .%T Network Time Protocol Version 4: Autokey Specification .%O RFC5906 .Re .Rs .%A H. Gerstung .%A C. Elliott .%A B. Haberman, Ed. .%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4) .%O RFC5907 .Re .Rs .%A R. Gayraud .%A B. Lourdelet .%T Network Time Protocol (NTP) Server Option for DHCPv6 .%O RFC5908 .Re _END_MDOC_SEE_ALSO; }; doc-section = { ds-type = 'BUGS'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_BUGS The .Nm utility has gotten rather fat. While not huge, it has gotten larger than might be desirable for an elevated-priority .Nm running on a workstation, particularly since many of the fancy features which consume the space were designed more with a busy primary server, rather than a high stratum workstation in mind. _END_MDOC_BUGS; }; doc-section = { ds-type = 'NOTES'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_NOTES Portions of this document came from FreeBSD. _END_MDOC_NOTES; }; diff --git a/contrib/ntp/ntpq/ntpq-opts.def b/contrib/ntp/ntpq/ntpq-opts.def index 85655a9d66cc..1189e81efe40 100644 --- a/contrib/ntp/ntpq/ntpq-opts.def +++ b/contrib/ntp/ntpq/ntpq-opts.def @@ -1,1032 +1,1032 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include copyright.def #include homerc.def #include autogen-version.def prog-name = "ntpq"; -prog-title = "standard NTP query program"; +prog-title = "query Network Time Protocol servers"; argument = '[ host ...]'; flag = { name = ipv4; flags-cant = ipv6; value = 4; descrip = "Force IPv4 name resolution"; doc = <<- _EndOfDoc_ Force resolution of following host names on the command line to the IPv4 namespace. _EndOfDoc_; }; flag = { name = ipv6; flags-cant = ipv4; value = 6; descrip = "Force IPv6 name resolution"; doc = <<- _EndOfDoc_ Force resolution of following host names on the command line to the IPv6 namespace. _EndOfDoc_; }; flag = { name = command; value = c; arg-type = string; descrip = "run a command and exit"; max = NOLIMIT; arg-name = cmd; call-proc = ntpq_custom_opt_handler; doc = <<- _EndOfDoc_ The following argument is interpreted as an interactive format command and is added to the list of commands to be executed on the specified host(s). _EndOfDoc_; }; #include debug-opt.def flag = { name = interactive; value = i; flags-cant = command, peers; descrip = "Force ntpq to operate in interactive mode"; doc = <<- _EndOfDoc_ Force @code{ntpq} to operate in interactive mode. Prompts will be written to the standard output and commands read from the standard input. _EndOfDoc_; }; flag = { name = numeric; value = n; descrip = "numeric host addresses"; doc = <<- _EndOfDoc_ Output all host addresses in dotted-quad numeric format rather than converting to the canonical host names. _EndOfDoc_; }; flag = { name = old-rv; descrip = "Always output status line with readvar"; doc = <<- _EndOfDoc_ By default, @code{ntpq} now suppresses the @code{associd=...} line that precedes the output of @code{readvar} (alias @code{rv}) when a single variable is requested, such as @code{ntpq -c "rv 0 offset"}. This option causes @code{ntpq} to include both lines of output for a single-variable @code{readvar}. Using an environment variable to preset this option in a script will enable both older and newer @code{ntpq} to behave identically in this regard. _EndOfDoc_; }; flag = { name = peers; value = p; descrip = "Print a list of the peers"; flags-cant = interactive; call-proc = ntpq_custom_opt_handler; doc = <<- _EndOfDoc_ Print a list of the peers known to the server as well as a summary of their state. This is equivalent to the 'peers' interactive command. _EndOfDoc_; }; flag = { name = refid; value = r; descrip = "Set default display type for S2+ refids"; arg-type = keyword; keyword = hash, ipv4; arg-default = ipv4; doc = <<- _EndOfDoc_ Set the default display format for S2+ refids. _EndOfDoc_; }; flag = { name = unconnected; value = u; descrip = "Use unconnected UDP to communicate with ntpd (default on Windows)"; doc = <<- _EndOfDoc_ Open an unconnected UDP association to ntpd (the default on Windows). _EndOfDoc_; }; flag = { name = wide; value = w; descrip = "Display the full 'remote' value"; doc = <<- _EndOfDoc_ Display the full value of the 'remote' value. If this requires more than 15 characters, display the full value, emit a newline, and continue the data display properly indented on the next line. _EndOfDoc_; }; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP .Pp The .Nm utility program is used to query NTP servers to monitor NTP operations and performance, requesting information about current state and/or changes in that state. The program may be run either in interactive mode or controlled using command line arguments. Requests to read and write arbitrary variables can be assembled, with raw and pretty-printed output options being available. The .Nm utility can also obtain and print a list of peers in a common format by sending multiple queries to the server. .Pp If one or more request options is included on the command line when .Nm is executed, each of the requests will be sent to the NTP servers running on each of the hosts given as command line arguments, or on localhost by default. If no request options are given, .Nm will attempt to read commands from the standard input and execute these on the NTP server running on the first host given on the command line, again defaulting to localhost when no other host is specified. The .Nm utility will prompt for commands if the standard input is a terminal device. .Pp .Nm uses NTP mode 6 packets to communicate with the NTP server, and hence can be used to query any compatible server on the network which permits it. Note that since NTP is a UDP protocol this communication will be somewhat unreliable, especially over large distances in terms of network topology. The .Nm utility makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable timeout time. .Pp Note that in contexts where a host name is expected, a .Fl 4 qualifier preceding the host name forces resolution to the IPv4 namespace, while a .Fl 6 qualifier forces resolution to the IPv6 namespace. For examples and usage, see the .Dq NTP Debugging Techniques page. .Pp Specifying a command line option other than .Fl i or .Fl n will cause the specified query (queries) to be sent to the indicated host(s) immediately. Otherwise, .Nm will attempt to read interactive format commands from the standard input. .Ss "Internal Commands" .Pp Interactive format commands consist of a keyword followed by zero to four arguments. Only enough characters of the full keyword to uniquely identify the command need be typed. .Pp A number of interactive format commands are executed entirely within the .Nm utility itself and do not result in NTP requests being sent to a server. These are described following. .Bl -tag -width "help [command]" -compact -offset indent .It Ic ? Op Ar command .It Ic help Op Ar command A .Ql \&? by itself will print a list of all the commands known to .Nm . A .Ql \&? followed by a command name will print function and usage information about the command. .It Ic addvars Ar name Ns Oo \&= Ns Ar value Oc Ns Op ,... .It Ic rmvars Ar name Ns Op ,... .It Ic clearvars .It Ic showvars The arguments to this command consist of a list of items of the form .Ar name Ns Op \&= Ns Ar value , where the .No \&= Ns Ar value is ignored, and can be omitted, in requests to the server to read variables. The .Nm utility maintains an internal list in which data to be included in messages can be assembled, and displayed or set using the .Ic readlist and .Ic writelist commands described below. The .Ic addvars command allows variables and their optional values to be added to the list. If more than one variable is to be added, the list should be comma-separated and not contain white space. The .Ic rmvars command can be used to remove individual variables from the list, while the .Ic clearvars command removes all variables from the list. The .Ic showvars command displays the current list of optional variables. .It Ic authenticate Op Cm yes Ns | Ns Cm no Normally .Nm does not authenticate requests unless they are write requests. The command .Ic authenticate Cm yes causes .Nm to send authentication with all requests it makes. Authenticated requests causes some servers to handle requests slightly differently. The command .Ic authenticate causes .Nm to display whether or not it is currently authenticating requests. .It Ic cooked Causes output from query commands to be "cooked", so that variables which are recognized by .Nm will have their values reformatted for human consumption. Variables which .Nm could not decode completely are marked with a trailing .Ql \&? . .It Ic debug Op Cm more Ns | Ns Cm less Ns | Ns Cm off With no argument, displays the current debug level. Otherwise, the debugging level is changed as indicated. .It Ic delay Op Ar milliseconds Specify a time interval to be added to timestamps included in requests which require authentication. This is used to enable (unreliable) server reconfiguration over long delay network paths or between machines whose clocks are unsynchronized. Actually the server does not now require timestamps in authenticated requests, so this command may be obsolete. Without any arguments, displays the current delay. .It Ic drefid Op Cm hash Ns | Ns Cm ipv4 Display refids as IPv4 or hash. Without any arguments, displays whether refids are shown as IPv4 addresses or hashes. .It Ic exit Exit .Nm . .It Ic host Op Ar name Set the host to which future queries will be sent. The .Ar name may be either a host name or a numeric address. Without any arguments, displays the current host. .It Ic hostnames Op Cm yes Ns | Ns Cm no If .Cm yes is specified, host names are printed in information displays. If .Cm no is specified, numeric addresses are printed instead. The default is .Cm yes , unless modified using the command line .Fl n switch. Without any arguments, displays whether host names or numeric addresses are shown. .It Ic keyid Op Ar keyid This command allows the specification of a key number to be used to authenticate configuration requests. This must correspond to the .Cm controlkey key number the server has been configured to use for this purpose. Without any arguments, displays the current .Ar keyid . .It Ic keytype Op Ar digest Specify the digest algorithm to use for authenticating requests, with default .Cm MD5 . If .Nm was built with OpenSSL support, and OpenSSL is installed, .Ar digest can be any message digest algorithm supported by OpenSSL. If no argument is given, the current .Ic keytype Ar digest algorithm used is displayed. .It Ic ntpversion Op Cm 1 Ns | Ns Cm 2 Ns | Ns Cm 3 Ns | Ns Cm 4 Sets the NTP version number which .Nm claims in packets. Defaults to 3, and note that mode 6 control messages (and modes, for that matter) didn't exist in NTP version 1. There appear to be no servers left which demand version 1. With no argument, displays the current NTP version that will be used when communicating with servers. .It Ic passwd This command prompts you to type in a password (which will not be echoed) which will be used to authenticate configuration requests. The password must correspond to the key configured for use by the NTP server for this purpose if such requests are to be successful. .It Ic poll Oo Ar n Oc Op Cm verbose Poll an NTP server in client mode .Ar n times. Poll not implemented yet. .It Ic quit Exit .Nm . .It Ic raw Causes all output from query commands is printed as received from the remote server. The only formating/interpretation done on the data is to transform nonascii data into a printable (but barely understandable) form. .It Ic timeout Op Ar milliseconds Specify a timeout period for responses to server queries. The default is about 5000 milliseconds. Without any arguments, displays the current timeout period. Note that since .Nm retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set. .It Ic version Display the version of the .Nm program. .El .Ss "Control Message Commands" Association ids are used to identify system, peer and clock variables. System variables are assigned an association id of zero and system name space, while each association is assigned a nonzero association id and peer namespace. Most control commands send a single message to the server and expect a single response message. The exceptions are the .Ic peers command, which sends a series of messages, and the .Ic mreadlist and .Ic mreadvar commands, which iterate over a range of associations. .Bl -tag -width "something" -compact -offset indent .It Ic apeers Display a list of peers in the form: .Dl [tally]remote refid assid st t when pool reach delay offset jitter where the output is just like the .Ic peers command except that the .Cm refid is displayed in hex format and the association number is also displayed. .It Ic associations Display a list of mobilized associations in the form: .Dl ind assid status conf reach auth condition last_event cnt .Bl -column -offset indent ".Sy Variable" "see the select field of the peer status word" .It Sy Variable Ta Sy Description .It Cm ind Ta index on this list .It Cm assid Ta association id .It Cm status Ta peer status word .It Cm conf Ta Cm yes : No persistent, Cm no : No ephemeral .It Cm reach Ta Cm yes : No reachable, Cm no : No unreachable .It Cm auth Ta Cm ok , Cm yes , Cm bad No and Cm none .It Cm condition Ta selection status \&(see the Cm select No field of the peer status word\&) .It Cm last_event Ta event report \&(see the Cm event No field of the peer status word\&) .It Cm cnt Ta event count \&(see the Cm count No field of the peer status word\&) .El .It Ic authinfo Display the authentication statistics counters: time since reset, stored keys, free keys, key lookups, keys not found, uncached keys, expired keys, encryptions, decryptions. .It Ic clocklist Op Ar associd .It Ic cl Op Ar associd Display all clock variables in the variable list for those associations supporting a reference clock. .It Ic clockvar Oo Ar associd Oc Oo Ar name Ns Oo \&= Ns Ar value Oc Ns Oc Ns Op ,... .It Ic cv Oo Ar associd Oc Oo Ar name Ns Oo \&= Ns Ar value Oc Ns Oc Ns Op ,... Display a list of clock variables for those associations supporting a reference clock. .It Ic :config Ar "configuration command line" Send the remainder of the command line, including whitespace, to the server as a run-time configuration command in the same format as a line in the configuration file. This command is experimental until further notice and clarification. Authentication is of course required. .It Ic config-from-file Ar filename Send each line of .Ar filename to the server as run-time configuration commands in the same format as lines in the configuration file. This command is experimental until further notice and clarification. Authentication is required. .It Ic ifstats Display status and statistics counters for each local network interface address: interface number, interface name and address or broadcast, drop, flag, ttl, mc, received, sent, send failed, peers, uptime. Authentication is required. .It Ic iostats Display network and reference clock I/O statistics: time since reset, receive buffers, free receive buffers, used receive buffers, low water refills, dropped packets, ignored packets, received packets, packets sent, packet send failures, input wakeups, useful input wakeups. .It Ic kerninfo Display kernel loop and PPS statistics: associd, status, pll offset, pll frequency, maximum error, estimated error, kernel status, pll time constant, precision, frequency tolerance, pps frequency, pps stability, pps jitter, calibration interval, calibration cycles, jitter exceeded, stability exceeded, calibration errors. As with other ntpq output, times are in milliseconds; very small values may be shown as exponentials. The precision value displayed is in milliseconds as well, unlike the precision system variable. .It Ic lassociations Perform the same function as the associations command, except display mobilized and unmobilized associations, including all clients. .It Ic lopeers Op Fl 4 Ns | Ns Fl 6 Display a list of all peers and clients showing .Cm dstadr (associated with the given IP version). .It Ic lpassociations Display the last obtained list of associations, including all clients. .It Ic lpeers Op Fl 4 Ns | Ns Fl 6 Display a list of all peers and clients (associated with the given IP version). .It Ic monstats Display monitor facility status, statistics, and limits: enabled, addresses, peak addresses, maximum addresses, reclaim above count, reclaim older than, kilobytes, maximum kilobytes. .It Ic mreadlist Ar associdlo Ar associdhi .It Ic mrl Ar associdlo Ar associdhi Perform the same function as the .Ic readlist command for a range of association ids. .It Ic mreadvar Ar associdlo Ar associdhi Oo Ar name Oc Ns Op ,... This range may be determined from the list displayed by any command showing associations. .It Ic mrv Ar associdlo Ar associdhi Oo Ar name Oc Ns Op ,... Perform the same function as the .Ic readvar command for a range of association ids. This range may be determined from the list displayed by any command showing associations. .It Xo Ic mrulist Oo Cm limited | Cm kod | Cm mincount Ns \&= Ns Ar count | .Cm laddr Ns \&= Ns Ar localaddr | Cm sort Ns \&= Ns Oo \&- Oc Ns Ar sortorder | .Cm resany Ns \&= Ns Ar hexmask | Cm resall Ns \&= Ns Ar hexmask Oc .Xc Display traffic counts of the most recently seen source addresses collected and maintained by the monitor facility. With the exception of .Cm sort Ns \&= Ns Oo \&- Oc Ns Ar sortorder , the options filter the list returned by .Xr ntpd 8 . The .Cm limited and .Cm kod options return only entries representing client addresses from which the last packet received triggered either discarding or a KoD response. The .Cm mincount Ns = Ns Ar count option filters entries representing less than .Ar count packets. The .Cm laddr Ns = Ns Ar localaddr option filters entries for packets received on any local address other than .Ar localaddr . .Cm resany Ns = Ns Ar hexmask and .Cm resall Ns = Ns Ar hexmask filter entries containing none or less than all, respectively, of the bits in .Ar hexmask , which must begin with .Cm 0x . The .Ar sortorder defaults to .Cm lstint and may be .Cm addr , .Cm avgint , .Cm count , .Cm lstint , or any of those preceded by .Ql \&- to reverse the sort order. The output columns are: .Bl -tag -width "something" -compact -offset indent .It Column Description .It Ic lstint Interval in seconds between the receipt of the most recent packet from this address and the completion of the retrieval of the MRU list by .Nm . .It Ic avgint Average interval in s between packets from this address. .It Ic rstr Restriction flags associated with this address. Most are copied unchanged from the matching .Ic restrict command, however 0x400 (kod) and 0x20 (limited) flags are cleared unless the last packet from this address triggered a rate control response. .It Ic r Rate control indicator, either a period, .Ic L or .Ic K for no rate control response, rate limiting by discarding, or rate limiting with a KoD response, respectively. .It Ic m Packet mode. .It Ic v Packet version number. .It Ic count Packets received from this address. .It Ic rport Source port of last packet from this address. .It Ic remote address host or DNS name, numeric address, or address followed by claimed DNS name which could not be verified in parentheses. .El .It Ic opeers Op Fl 4 | Fl 6 Obtain and print the old-style list of all peers and clients showing .Cm dstadr (associated with the given IP version), rather than the .Cm refid . .It Ic passociations Perform the same function as the .Ic associations command, except that it uses previously stored data rather than making a new query. .It Ic peers Display a list of peers in the form: .Dl [tally]remote refid st t when pool reach delay offset jitter .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm [tally] single-character code indicating current value of the .Ic select field of the .Lk decode.html#peer "peer status word" .It Cm remote host name (or IP number) of peer. The value displayed will be truncated to 15 characters unless the .Nm .Fl w option is given, in which case the full value will be displayed on the first line, and if too long, the remaining data will be displayed on the next line. .It Cm refid source IP address or .Lk decode.html#kiss "'kiss code" .It Cm st stratum: 0 for local reference clocks, 1 for servers with local reference clocks, ..., 16 for unsynchronized server clocks .It Cm t .Ic u : unicast or manycast client, .Ic b : broadcast or multicast client, .Ic p : pool source, .Ic l : local (reference clock), .Ic s : symmetric (peer), .Ic A : manycast server, .Ic B : broadcast server, .Ic M : multicast server .It Cm when time in seconds, minutes, hours, or days since the last packet was received, or .Ql \&- if a packet has never been received .It Cm poll poll interval (s) .It Cm reach reach shift register (octal) .It Cm delay roundtrip delay .It Cm offset offset of server relative to this host .It Cm jitter offset RMS error estimate. .El .It Ic pstats Ar associd Display the statistics for the peer with the given .Ar associd : associd, status, remote host, local address, time last received, time until next send, reachability change, packets sent, packets received, bad authentication, bogus origin, duplicate, bad dispersion, bad reference time, candidate order. .It Ic readlist Op Ar associd .It Ic rl Op Ar associd Display all system or peer variables. If the .Ar associd is omitted, it is assumed to be zero. .It Ic readvar Op Ar associd Ar name Ns Oo Ns = Ns Ar value Oc Op , ... .It Ic rv Op Ar associd Ar name Ns Oo Ns = Ns Ar value Oc Op , ... Display the specified system or peer variables. If .Ar associd is zero, the variables are from the .Sx System Variables name space, otherwise they are from the .Sx Peer Variables name space. The .Ar associd is required, as the same name can occur in both spaces. If no .Ar name is included, all operative variables in the name space are displayed. In this case only, if the .Ar associd is omitted, it is assumed to be zero. Multiple names are specified with comma separators and without whitespace. Note that time values are represented in milliseconds and frequency values in parts-per-million (PPM). Some NTP timestamps are represented in the format .Ar YYYY Ns Ar MM Ar DD Ar TTTT , where .Ar YYYY is the year, .Ar MM the month of year, .Ar DD the day of month and .Ar TTTT the time of day. .It Ic reslist Display the access control (restrict) list for .Nm . Authentication is required. .It Ic saveconfig Ar filename Save the current configuration, including any runtime modifications made by .Ic :config or .Ic config-from-file , to the NTP server host file .Ar filename . This command will be rejected by the server unless .Lk miscopt.html#saveconfigdir "saveconfigdir" appears in the .Xr ntpd 8 configuration file. .Ar filename can use .Xr date 1 format specifiers to substitute the current date and time, for example, .D1 Ic saveconfig Pa ntp-%Y%m%d-%H%M%S.conf . The filename used is stored in system variable .Cm savedconfig . Authentication is required. .It Ic sysinfo Display system operational summary: associd, status, system peer, system peer mode, leap indicator, stratum, log2 precision, root delay, root dispersion, reference id, reference time, system jitter, clock jitter, clock wander, broadcast delay, symm. auth. delay. .It Ic sysstats Display system uptime and packet counts maintained in the protocol module: uptime, sysstats reset, packets received, current version, older version, bad length or format, authentication failed, declined, restricted, rate limited, KoD responses, processed for time. .It Ic timerstats Display interval timer counters: time since reset, timer overruns, calls to transmit. .It Ic writelist Ar associd Set all system or peer variables included in the variable list. .It Ic writevar Ar associd Ar name Ns = Ns Ar value Op , ... Set the specified variables in the variable list. If the .Ar associd is zero, the variables are from the .Sx System Variables name space, otherwise they are from the .Sx Peer Variables name space. The .Ar associd is required, as the same name can occur in both spaces. Authentication is required. .El .Ss Status Words and Kiss Codes The current state of the operating program is shown in a set of status words maintained by the system. Status information is also available on a per-association basis. These words are displayed by the .Ic readlist and .Ic associations commands both in hexadecimal and in decoded short tip strings. The codes, tips and short explanations are documented on the .Lk decode.html "Event Messages and Status Words" page. The page also includes a list of system and peer messages, the code for the latest of which is included in the status word. .Pp Information resulting from protocol machine state transitions is displayed using an informal set of ASCII strings called .Lk decode.html#kiss "kiss codes" . The original purpose was for kiss-o'-death (KoD) packets sent by the server to advise the client of an unusual condition. They are now displayed, when appropriate, in the reference identifier field in various billboards. .Ss System Variables The following system variables appear in the .Ic readlist billboard. Not all variables are displayed in some configurations. .Pp .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm status .Lk decode.html#sys "system status word" .It Cm version NTP software version and build time .It Cm processor hardware platform and version .It Cm system operating system and version .It Cm leap leap warning indicator (0-3) .It Cm stratum stratum (1-15) .It Cm precision precision (log2 s) .It Cm rootdelay total roundtrip delay to the primary reference clock .It Cm rootdisp total dispersion to the primary reference clock .It Cm refid reference id or .Lk decode.html#kiss "kiss code" .It Cm reftime reference time .It Ic clock date and time of day .It Cm peer system peer association id .It Cm tc time constant and poll exponent (log2 s) (3-17) .It Cm mintc minimum time constant (log2 s) (3-10) .It Cm offset combined offset of server relative to this host .It Cm frequency frequency drift (PPM) relative to hardware clock .It Cm sys_jitter combined system jitter .It Cm clk_wander clock frequency wander (PPM) .It Cm clk_jitter clock jitter .It Cm tai TAI-UTC offset (s) .It Cm leapsec NTP seconds when the next leap second is/was inserted .It Cm expire NTP seconds when the NIST leapseconds file expires .El The jitter and wander statistics are exponentially-weighted RMS averages. The system jitter is defined in the NTPv4 specification; the clock jitter statistic is computed by the clock discipline module. .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional system variables are displayed, including some or all of the following, depending on the particular Autokey dance: .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm host Autokey host name for this host .It Cm ident Autokey group name for this host .It Cm flags host flags (see Autokey specification) .It Cm digest OpenSSL message digest algorithm .It Cm signature OpenSSL digest/signature scheme .It Cm update NTP seconds at last signature update .It Cm cert certificate subject, issuer and certificate flags .It Cm until NTP seconds when the certificate expires .El .Ss Peer Variables The following peer variables appear in the .Ic readlist billboard for each association. Not all variables are displayed in some configurations. .Pp .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm associd association id .It Cm status .Lk decode.html#peer "peer status word" .It Cm srcadr source (remote) IP address .It Cm srcport source (remote) port .It Cm dstadr destination (local) IP address .It Cm dstport destination (local) port .It Cm leap leap indicator (0-3) .It Cm stratum stratum (0-15) .It Cm precision precision (log2 s) .It Cm rootdelay total roundtrip delay to the primary reference clock .It Cm rootdisp total root dispersion to the primary reference clock .It Cm refid reference id or .Lk decode.html#kiss "kiss code" .It Cm reftime reference time .It Cm rec last packet received time .It Cm reach reach register (octal) .It Cm unreach unreach counter .It Cm hmode host mode (1-6) .It Cm pmode peer mode (1-5) .It Cm hpoll host poll exponent (log2 s) (3-17) .It Cm ppoll peer poll exponent (log2 s) (3-17) .It Cm headway headway (see .Lk rate.html "Rate Management and the Kiss-o'-Death Packet" ) .It Cm flash .Lk decode.html#flash "flash status word" .It Cm keyid symmetric key id .It Cm offset filter offset .It Cm delay filter delay .It Cm dispersion filter dispersion .It Cm jitter filter jitter .It Cm bias unicast/broadcast bias .It Cm xleave interleave delay (see .Lk xleave.html "NTP Interleaved Modes" ) .El The .Cm bias variable is calculated when the first broadcast packet is received after the calibration volley. It represents the offset of the broadcast subgraph relative to the unicast subgraph. The .Cm xleave variable appears only for the interleaved symmetric and interleaved modes. It represents the internal queuing, buffering and transmission delays for the preceding packet. .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional peer variables are displayed, including the following: .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm flags peer flags (see Autokey specification) .It Cm host Autokey server name .It Cm flags peer flags (see Autokey specification) .It Cm signature OpenSSL digest/signature scheme .It Cm initsequence initial key id .It Cm initkey initial key index .It Cm timestamp Autokey signature timestamp .It Cm ident Autokey group name for this association .El .Ss Clock Variables The following clock variables appear in the .Ic clocklist billboard for each association with a reference clock. Not all variables are displayed in some configurations. .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm associd association id .It Cm status .Lk decode.html#clock "clock status word" .It Cm device device description .It Cm timecode ASCII time code string (specific to device) .It Cm poll poll messages sent .It Cm noreply no reply .It Cm badformat bad format .It Cm baddata bad date or time .It Cm fudgetime1 fudge time 1 .It Cm fudgetime2 fudge time 2 .It Cm stratum driver stratum .It Cm refid driver reference id .It Cm flags driver flags .El _END_PROG_MDOC_DESCRIP; }; diff --git a/contrib/ntp/sntp/sntp-opts.def b/contrib/ntp/sntp/sntp-opts.def index 7664b1bf08b9..d468b6ef8bf5 100644 --- a/contrib/ntp/sntp/sntp-opts.def +++ b/contrib/ntp/sntp/sntp-opts.def @@ -1,337 +1,337 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include autogen-version.def #include copyright.def prog-name = "sntp"; -prog-title = "standard Simple Network Time Protocol client program"; +prog-title = "reference Simple Network Time Protocol client"; argument = '[ hostname-or-IP ...]'; #include homerc.def long-opts; config-header = "config.h"; environrc; #include version.def flag = { name = ipv4; value = 4; flags-cant = ipv6; descrip = "Force IPv4 DNS name resolution"; doc = <<- _EndOfDoc_ Force DNS resolution of the following host names on the command line to the IPv4 namespace. _EndOfDoc_; }; flag = { name = ipv6; value = 6; flags-cant = ipv4; descrip = "Force IPv6 DNS name resolution"; doc = <<- _EndOfDoc_ Force DNS resolution of the following host names on the command line to the IPv6 namespace. _EndOfDoc_; }; flag = { name = authentication; value = a; descrip = "Enable authentication with the key @var{auth-keynumber}"; arg-type = number; arg-name = "auth-keynumber"; doc = <<- _EndOfDoc_ Enable authentication using the key specified in this option's argument. The argument of this option is the @option{keyid}, a number specified in the @option{keyfile} as this key's identifier. See the @option{keyfile} option (@option{-k}) for more details. _EndOfDoc_; }; flag = { name = broadcast; value = b; descrip = "Listen to the address specified for broadcast time sync"; arg-type = string; arg-name = "broadcast-address"; max = NOLIMIT; stack-arg; doc = <<- _EndOfDoc_ If specified @code{sntp} will listen to the specified address for NTP broadcasts. The default maximum wait time can (and probably should) be modified with @option{-t}. _EndOfDoc_; }; flag = { name = concurrent; value = c; descrip = "Concurrently query all IPs returned for host-name"; arg-type = string; arg-name = "host-name"; max = NOLIMIT; stack-arg; doc = <<- _EndOfDoc_ Requests from an NTP "client" to a "server" should never be sent more rapidly than one every 2 seconds. By default, any IPs returned as part of a DNS lookup are assumed to be for a single instance of @code{ntpd}, and therefore @code{sntp} will send queries to these IPs one after another, with a 2-second gap in between each query. The @option{-c} or @option{--concurrent} flag says that any IPs returned for the DNS lookup of the supplied host-name are on different machines, so we can send concurrent queries. _EndOfDoc_; }; #include debug-opt.def flag = { name = gap; value = g; descrip = "The gap (in milliseconds) between time requests"; arg-type = number; arg-name = "milliseconds"; arg-default = 50; doc = <<- _EndOfDoc_ Since we're only going to use the first valid response we get and there is benefit to specifying a good number of servers to query, separate the queries we send out by the specified number of milliseconds. _EndOfDoc_; }; flag = { name = kod; value = K; arg-type = file; arg-name = "file-name"; arg-default = "/var/db/ntp-kod"; descrip = "KoD history filename"; doc = <<- _EndOfDoc_ Specifies the filename to be used for the persistent history of KoD responses received from servers. If the file does not exist, a warning message will be displayed. The file will not be created. _EndOfDoc_; }; flag = { name = keyfile; value = k; descrip = "Look in this file for the key specified with @option{-a}"; arg-type = file; arg-name = "file-name"; arg-default = "/etc/ntp.keys"; doc = <<- _EndOfDoc_ This option specifies the keyfile. @code{sntp} will search for the key specified with @option{-a} @file{keyno} in this file. See @command{ntp.keys(5)} for more information. _EndOfDoc_; }; flag = { name = logfile; value = l; arg-type = file; arg-name = "file-name"; descrip = "Log to specified logfile"; doc = <<- _EndOfDoc_ This option causes the client to write log messages to the specified @file{logfile}. _EndOfDoc_; }; flag = { name = steplimit; value = M; arg-type = number; arg-range = "0->"; descrip = "Adjustments less than @var{steplimit} msec will be slewed"; doc = <<- _EndOfDoc_ If the time adjustment is less than @file{steplimit} milliseconds, slew the amount using @command{adjtime(2)}. Otherwise, step the correction using @command{settimeofday(2)}. The default value is 0, which means all adjustments will be stepped. This is a feature, as different situations demand different values. _EndOfDoc_; }; flag = { name = ntpversion; value = o; descrip = "Send @var{int} as our NTP protocol version"; arg-type = number; arg-default = 4; arg-range = "0->7"; doc = <<- _EndOfDoc_ When sending requests to a remote server, tell them we are running NTP protocol version @file{ntpversion} . _EndOfDoc_; }; flag = { name = usereservedport; value = r; descrip = "Use the NTP Reserved Port (port 123)"; doc = <<- _EndOfDoc_ Use port 123, which is reserved for NTP, for our network communications. _EndOfDoc_; }; flag = { name = step; value = S; descrip = "OK to 'step' the time with @command{settimeofday(2)}"; doc = <<- _EndOfDoc_ _EndOfDoc_; }; flag = { name = slew; value = s; descrip = "OK to 'slew' the time with @command{adjtime(2)}"; doc = <<- _EndOfDoc_ _EndOfDoc_; }; flag = { name = timeout; value = t; descrip = "The number of seconds to wait for responses"; arg-type = number; arg-name = "seconds"; arg-default = 5; doc = <<- _EndOfDoc_ When waiting for a reply, @code{sntp} will wait the number of seconds specified before giving up. The default should be more than enough for a unicast response. If @code{sntp} is only waiting for a broadcast response a longer timeout is likely needed. _EndOfDoc_; }; flag = { name = "wait"; descrip = "Wait for pending replies (if not setting the time)"; disable = no; enabled; settable; doc = <<- _EndOfDoc_ If we are not setting the time, wait for all pending responses. _EndOfDoc_; }; /* explain: Additional information whenever the usage routine is invoked */ explain = <<- _END_EXPLAIN _END_EXPLAIN; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP .Nm can be used as an SNTP client to query a NTP or SNTP server and either display the time or set the local system's time (given suitable privilege). It can be run as an interactive command or from a .Ic cron job. NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol) are defined and described by RFC 5905. .Pp The default is to write the estimated correct local date and time (i.e. not UTC) to the standard output in a format like: .Ic "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 [host] IP sN'" where the .Ic "'(+0800)'" means that to get to UTC from the reported local time one must add 8 hours and 0 minutes, the .Ic "'+4.567'" indicates the local clock is 4.567 seconds behind the correct time (so 4.567 seconds must be added to the local clock to get it to be correct). Note that the number of decimals printed for this value will change based on the reported precision of the server. .Ic "'+/- 0.089'" is the reported .Em synchronization distance (in seconds), which represents the maximum error due to all causes. If the server does not report valid data needed to calculate the synchronization distance, this will be reported as .Ic "'+/- ?'" . If the .Em host is different from the .Em IP , both will be displayed. Otherwise, only the .Em IP is displayed. Finally, the .Em stratum of the host is reported and the leap indicator is decoded and displayed. _END_PROG_MDOC_DESCRIP; }; doc-section = { ds-type = 'USAGE'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_USAGE .Bl -tag -width indent .It Li "sntp ntpserver.somewhere" is the simplest use of this program and can be run as an unprivileged command to check the current time and error in the local clock. .It Li "sntp -Ss -M 128 ntpserver.somewhere" With suitable privilege, run as a command or from a .Xr cron 8 job, .Ic "sntp -Ss -M 128 ntpserver.somewhere" will request the time from the server, and if that server reports that it is synchronized then if the offset adjustment is less than 128 milliseconds the correction will be slewed, and if the correction is more than 128 milliseconds the correction will be stepped. .It Li "sntp -S ntpserver.somewhere" With suitable privilege, run as a command or from a .Xr cron 8 job, .Ic "sntp -S ntpserver.somewhere" will set (step) the local clock from a synchronized specified server, like the (deprecated) .Xr ntpdate 1ntpdatemdoc , or .Xr rdate 8 commands. .El _END_MDOC_USAGE; }; doc-section = { ds-type = 'AUTHORS'; ds-format = 'mdoc'; ds-text = <<- _END_MDOC_AUTHORS .An "Johannes Maximilian Kuehn" .An "Harlan Stenn" .An "Dave Hart" _END_MDOC_AUTHORS; }; diff --git a/contrib/ntp/util/ntp-keygen-opts.def b/contrib/ntp/util/ntp-keygen-opts.def index 632dbbec778d..5c06bded15fd 100644 --- a/contrib/ntp/util/ntp-keygen-opts.def +++ b/contrib/ntp/util/ntp-keygen-opts.def @@ -1,1298 +1,1298 @@ /* -*- Mode: Text -*- */ autogen definitions options; #include copyright.def #include homerc.def #include autogen-version.def prog-name = "ntp-keygen"; -prog-title = "Create a NTP host key"; +prog-title = "create a Network Time Protocol host key"; package = ntp; include = '#include '; #include version.def flag = { value = b; name = imbits; arg-type = number; arg-name = imbits; arg-range = '256->2048'; ifdef = AUTOKEY; descrip = "identity modulus bits"; doc = <<- _EndOfDoc_ The number of bits in the identity modulus. The default is 512. _EndOfDoc_; }; flag = { value = c; name = certificate; arg-type = string; arg-name = scheme; ifdef = AUTOKEY; descrip = "certificate scheme"; doc = <<- _EndOfDoc_ scheme is one of RSA-MD2, RSA-MD5, RSA-MDC2, RSA-SHA, RSA-SHA1, RSA-RIPEMD160, DSA-SHA, or DSA-SHA1. Select the certificate signature encryption/message digest scheme. Note that RSA schemes must be used with a RSA sign key and DSA schemes must be used with a DSA sign key. The default without this option is RSA-MD5. _EndOfDoc_; }; flag = { value = C; name = cipher; arg-type = string; arg-name = cipher; ifdef = AUTOKEY; descrip = "privatekey cipher"; doc = <<- _EndOfDoc_ Select the cipher which is used to encrypt the files containing private keys. The default is three-key triple DES in CBC mode, equivalent to "@code{-C des-ede3-cbc}". The openssl tool lists ciphers available in "@code{openssl -h}" output. _EndOfDoc_; }; #include debug-opt.def flag = { value = e; name = id-key; ifdef = AUTOKEY; descrip = "Write IFF or GQ identity keys"; doc = <<- _EndOfDoc_ Write the public parameters from the IFF or GQ client keys to the standard output. This is intended for automatic key distribution by email. _EndOfDoc_; }; flag = { value = G; name = gq-params; ifdef = AUTOKEY; descrip = "Generate GQ parameters and keys"; doc = <<- _EndOfDoc_ Generate parameters and keys for the GQ identification scheme, obsoleting any that may exist. _EndOfDoc_; }; flag = { value = H; name = host-key; ifdef = AUTOKEY; descrip = "generate RSA host key"; doc = <<- _EndOfDoc_ Generate new host keys, obsoleting any that may exist. _EndOfDoc_; }; flag = { value = I; name = iffkey; ifdef = AUTOKEY; descrip = "generate IFF parameters"; doc = <<- _EndOfDoc_ Generate parameters for the IFF identification scheme, obsoleting any that may exist. _EndOfDoc_; }; flag = { value = i; name = ident; ifdef = AUTOKEY; arg-type = string; arg-name = group; descrip = "set Autokey group name"; doc = <<- _EndOfDoc_ Set the optional Autokey group name to name. This is used in the file name of IFF, GQ, and MV client parameters files. In that role, the default is the host name if this option is not provided. The group name, if specified using @code{-i/--ident} or using @code{-s/--subject-name} following an '@code{@@}' character, is also a part of the self-signed host certificate subject and issuer names in the form @code{host@@group} and should match the '@code{crypto ident}' or '@code{server ident}' configuration in the @code{ntpd} configuration file. _EndOfDoc_; }; flag = { value = l; name = lifetime; ifdef = AUTOKEY; arg-type = number; arg-name = lifetime; descrip = "set certificate lifetime"; doc = <<- _EndOfDoc_ Set the certificate expiration to lifetime days from now. _EndOfDoc_; }; flag = { value = m; name = modulus; arg-type = number; arg-name = modulus; arg-range = '256->2048'; ifdef = AUTOKEY; descrip = "prime modulus"; doc = <<- _EndOfDoc_ The number of bits in the prime modulus. The default is 512. _EndOfDoc_; }; flag = { value = M; name = md5key; descrip = "generate symmetric keys"; doc = <<- _EndOfDoc_ Generate symmetric keys, obsoleting any that may exist. _EndOfDoc_; }; flag = { value = P; name = pvt-cert; ifdef = AUTOKEY; descrip = "generate PC private certificate"; doc = <<- _EndOfDoc_ Generate a private certificate. By default, the program generates public certificates. _EndOfDoc_; }; flag = { value = p; name = password; // was: pvt-passwd; ifdef = AUTOKEY; arg-type = string; arg-name = passwd; descrip = "local private password"; doc = <<- _EndOfDoc_ Local files containing private data are encrypted with the DES-CBC algorithm and the specified password. The same password must be specified to the local ntpd via the "crypto pw password" configuration command. The default password is the local hostname. _EndOfDoc_; }; flag = { value = q; name = export-passwd; // Was: get-pvt-passwd; ifdef = AUTOKEY; arg-type = string; arg-name = passwd; descrip = "export IFF or GQ group keys with password"; doc = <<- _EndOfDoc_ Export IFF or GQ identity group keys to the standard output, encrypted with the DES-CBC algorithm and the specified password. The same password must be specified to the remote ntpd via the "crypto pw password" configuration command. See also the option --id-key (-e) for unencrypted exports. _EndOfDoc_; }; flag = { value = s; name = subject-name; arg-type = string; arg-name = host@group; ifdef = AUTOKEY; descrip = "set host and optionally group name"; doc = <<- _EndOfDoc_ Set the Autokey host name, and optionally, group name specified following an '@code{@@}' character. The host name is used in the file name of generated host and signing certificates, without the group name. The host name, and if provided, group name are used in @code{host@@group} form for the host certificate subject and issuer fields. Specifying '@code{-s @@group}' is allowed, and results in leaving the host name unchanged while appending @code{@@group} to the subject and issuer fields, as with @code{-i group}. The group name, or if not provided, the host name are also used in the file names of IFF, GQ, and MV client parameter files. _EndOfDoc_; }; flag = { value = S; name = sign-key; arg-type = string; arg-name = sign; ifdef = AUTOKEY; descrip = "generate sign key (RSA or DSA)"; doc = <<- _EndOfDoc_ Generate a new sign key of the designated type, obsoleting any that may exist. By default, the program uses the host key as the sign key. _EndOfDoc_; }; flag = { value = T; name = trusted-cert; ifdef = AUTOKEY; descrip = "trusted certificate (TC scheme)"; doc = <<- _EndOfDoc_ Generate a trusted certificate. By default, the program generates a non-trusted certificate. _EndOfDoc_; }; flag = { value = V; name = mv-params; arg-type = number; arg-name = num; ifdef = AUTOKEY; descrip = "generate MV parameters"; doc = <<- _EndOfDoc_ Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme. _EndOfDoc_; }; flag = { value = v; name = mv-keys; arg-type = number; arg-name = num; ifdef = AUTOKEY; descrip = "update MV keys"; }; /* explain: Additional information whenever the usage routine is invoked */ explain = <<- _END_EXPLAIN _END_EXPLAIN; doc-section = { ds-type = 'DESCRIPTION'; ds-format = 'mdoc'; ds-text = <<- _END_PROG_MDOC_DESCRIP This program generates cryptographic data files used by the NTPv4 authentication and identification schemes. It can generate message digest keys used in symmetric key cryptography and, if the OpenSSL software library has been installed, it can generate host keys, signing keys, certificates, and identity keys and parameters used in Autokey public key cryptography. These files are used for cookie encryption, digital signature, and challenge/response identification algorithms compatible with the Internet standard security infrastructure. .Pp The message digest symmetric keys file is generated in a format compatible with NTPv3. All other files are in PEM-encoded printable ASCII format, so they can be embedded as MIME attachments in email to other sites and certificate authorities. By default, files are not encrypted. .Pp When used to generate message digest symmetric keys, the program produces a file containing ten pseudo-random printable ASCII strings suitable for the MD5 message digest algorithm included in the distribution. If the OpenSSL library is installed, it produces an additional ten hex-encoded random bit strings suitable for SHA1, AES-128-CMAC, and other message digest algorithms. The message digest symmetric keys file must be distributed and stored using secure means beyond the scope of NTP itself. Besides the keys used for ordinary NTP associations, additional keys can be defined as passwords for the .Xr ntpq 1ntpqmdoc and .Xr ntpdc 1ntpdcmdoc utility programs. .Pp The remaining generated files are compatible with other OpenSSL applications and other Public Key Infrastructure (PKI) resources. Certificates generated by this program are compatible with extant industry practice, although some users might find the interpretation of X509v3 extension fields somewhat liberal. However, the identity keys are probably not compatible with anything other than Autokey. .Pp Some files used by this program are encrypted using a private password. The .Fl p option specifies the read password for local encrypted files and the .Fl q option the write password for encrypted files sent to remote sites. If no password is specified, the host name returned by the Unix .Xr hostname 1 command, normally the DNS name of the host, is used as the the default read password, for convenience. The .Nm program prompts for the password if it reads an encrypted file and the password is missing or incorrect. If an encrypted file is read successfully and no write password is specified, the read password is used as the write password by default. .Pp The .Cm pw option of the .Ic crypto .Xr ntpd 1ntpdmdoc configuration command specifies the read password for previously encrypted local files. This must match the local read password used by this program. If not specified, the host name is used. Thus, if files are generated by this program without an explicit password, they can be read back by .Xr ntpd 1ntpdmdoc without specifying an explicit password but only on the same host. If the write password used for encryption is specified as the host name, these files can be read by that host with no explicit password. .Pp Normally, encrypted files for each host are generated by that host and used only by that host, although exceptions exist as noted later on this page. The symmetric keys file, normally called .Pa ntp.keys , is usually installed in .Pa /etc . Other files and links are usually installed in .Pa /usr/local/etc , which is normally in a shared filesystem in NFS-mounted networks and cannot be changed by shared clients. In these cases, NFS clients can specify the files in another directory such as .Pa /etc using the .Ic keysdir .Xr ntpd 1ntpdmdoc configuration file command. .Pp This program directs commentary and error messages to the standard error stream .Pa stderr and remote files to the standard output stream .Pa stdout where they can be piped to other applications or redirected to files. The names used for generated files and links all begin with the string .Pa ntpkey\&* and include the file type, generating host and filestamp, as described in the .Sx "Cryptographic Data Files" section below. .Ss Running the Program The safest way to run the .Nm program is logged in directly as root. The recommended procedure is change to the .Ar keys directory, usually .Pa /usr/local/etc , then run the program. .Pp To test and gain experience with Autokey concepts, log in as root and change to the .Ar keys directory, usually .Pa /usr/local/etc . When run for the first time, or if all files with names beginning with .Pa ntpkey\&* have been removed, use the .Nm command without arguments to generate a default .Cm RSA host key and matching .Cm RSA-MD5 certificate file with expiration date one year hence, which is all that is necessary in many cases. The program also generates soft links from the generic names to the respective files. If run again without options, the program uses the existing keys and parameters and generates a new certificate file with new expiration date one year hence, and soft link. .Pp The host key is used to encrypt the cookie when required and so must be .Cm RSA type. By default, the host key is also the sign key used to encrypt signatures. When necessary, a different sign key can be specified and this can be either .Cm RSA or .Cm DSA type. By default, the message digest type is .Cm MD5 , but any combination of sign key type and message digest type supported by the OpenSSL library can be specified, including those using the .Cm AES128CMAC , MD2 , MD5 , MDC2 , SHA , SHA1 and .Cm RIPE160 message digest algorithms. However, the scheme specified in the certificate must be compatible with the sign key. Certificates using any digest algorithm are compatible with .Cm RSA sign keys; however, only .Cm SHA and .Cm SHA1 certificates are compatible with .Cm DSA sign keys. .Pp Private/public key files and certificates are compatible with other OpenSSL applications and very likely other libraries as well. Certificates or certificate requests derived from them should be compatible with extant industry practice, although some users might find the interpretation of X509v3 extension fields somewhat liberal. However, the identification parameter files, although encoded as the other files, are probably not compatible with anything other than Autokey. .Pp Running the program as other than root and using the Unix .Xr su 1 command to assume root may not work properly, since by default the OpenSSL library looks for the random seed file .Pa .rnd in the user home directory. However, there should be only one .Pa .rnd , most conveniently in the root directory, so it is convenient to define the .Ev RANDFILE environment variable used by the OpenSSL library as the path to .Pa .rnd . .Pp Installing the keys as root might not work in NFS-mounted shared file systems, as NFS clients may not be able to write to the shared keys directory, even as root. In this case, NFS clients can specify the files in another directory such as .Pa /etc using the .Ic keysdir .Xr ntpd 1ntpdmdoc configuration file command. There is no need for one client to read the keys and certificates of other clients or servers, as these data are obtained automatically by the Autokey protocol. .Pp Ordinarily, cryptographic files are generated by the host that uses them, but it is possible for a trusted agent (TA) to generate these files for other hosts; however, in such cases files should always be encrypted. The subject name and trusted name default to the hostname of the host generating the files, but can be changed by command line options. It is convenient to designate the owner name and trusted name as the subject and issuer fields, respectively, of the certificate. The owner name is also used for the host and sign key files, while the trusted name is used for the identity files. .Pp All files are installed by default in the keys directory .Pa /usr/local/etc , which is normally in a shared filesystem in NFS-mounted networks. The actual location of the keys directory and each file can be overridden by configuration commands, but this is not recommended. Normally, the files for each host are generated by that host and used only by that host, although exceptions exist as noted later on this page. .Pp Normally, files containing private values, including the host key, sign key and identification parameters, are permitted root read/write-only; while others containing public values are permitted world readable. Alternatively, files containing private values can be encrypted and these files permitted world readable, which simplifies maintenance in shared file systems. Since uniqueness is insured by the .Ar hostname and .Ar filestamp file name extensions, the files for an NTP server and dependent clients can all be installed in the same shared directory. .Pp The recommended practice is to keep the file name extensions when installing a file and to install a soft link from the generic names specified elsewhere on this page to the generated files. This allows new file generations to be activated simply by changing the link. If a link is present, .Xr ntpd 1ntpdmdoc follows it to the file name to extract the .Ar filestamp . If a link is not present, .Xr ntpd 1ntpdmdoc extracts the .Ar filestamp from the file itself. This allows clients to verify that the file and generation times are always current. The .Nm program uses the same .Ar filestamp extension for all files generated at one time, so each generation is distinct and can be readily recognized in monitoring data. .Pp Run the command on as many hosts as necessary. Designate one of them as the trusted host (TH) using .Nm with the .Fl T option and configure it to synchronize from reliable Internet servers. Then configure the other hosts to synchronize to the TH directly or indirectly. A certificate trail is created when Autokey asks the immediately ascendant host towards the TH to sign its certificate, which is then provided to the immediately descendant host on request. All group hosts should have acyclic certificate trails ending on the TH. .Pp The host key is used to encrypt the cookie when required and so must be RSA type. By default, the host key is also the sign key used to encrypt signatures. A different sign key can be assigned using the .Fl S option and this can be either .Cm RSA or .Cm DSA type. By default, the signature message digest type is .Cm MD5 , but any combination of sign key type and message digest type supported by the OpenSSL library can be specified using the .Fl c option. .Pp The rules say cryptographic media should be generated with proventic filestamps, which means the host should already be synchronized before this program is run. This of course creates a chicken-and-egg problem when the host is started for the first time. Accordingly, the host time should be set by some other means, such as eyeball-and-wristwatch, at least so that the certificate lifetime is within the current year. After that and when the host is synchronized to a proventic source, the certificate should be re-generated. .Pp Additional information on trusted groups and identity schemes is on the .Dq Autokey Public-Key Authentication page. .Pp File names begin with the prefix .Pa ntpkey Ns _ and end with the suffix .Pa _ Ns Ar hostname . Ar filestamp , where .Ar hostname is the owner name, usually the string returned by the Unix .Xr hostname 1 command, and .Ar filestamp is the NTP seconds when the file was generated, in decimal digits. This both guarantees uniqueness and simplifies maintenance procedures, since all files can be quickly removed by a .Ic rm Pa ntpkey\&* command or all files generated at a specific time can be removed by a .Ic rm Pa \&* Ns Ar filestamp command. To further reduce the risk of misconfiguration, the first two lines of a file contain the file name and generation date and time as comments. .Ss Trusted Hosts and Groups Each cryptographic configuration involves selection of a signature scheme and identification scheme, called a cryptotype, as explained in the .Sx Authentication Options section of .Xr ntp.conf 5 . The default cryptotype uses .Cm RSA encryption, .Cm MD5 message digest and .Cm TC identification. First, configure a NTP subnet including one or more low-stratum trusted hosts from which all other hosts derive synchronization directly or indirectly. Trusted hosts have trusted certificates; all other hosts have nontrusted certificates. These hosts will automatically and dynamically build authoritative certificate trails to one or more trusted hosts. A trusted group is the set of all hosts that have, directly or indirectly, a certificate trail ending at a trusted host. The trail is defined by static configuration file entries or dynamic means described on the .Sx Automatic NTP Configuration Options section of .Xr ntp.conf 5 . .Pp On each trusted host as root, change to the keys directory. To insure a fresh fileset, remove all .Pa ntpkey files. Then run .Nm .Fl T to generate keys and a trusted certificate. On all other hosts do the same, but leave off the .Fl T flag to generate keys and nontrusted certificates. When complete, start the NTP daemons beginning at the lowest stratum and working up the tree. It may take some time for Autokey to instantiate the certificate trails throughout the subnet, but setting up the environment is completely automatic. .Pp If it is necessary to use a different sign key or different digest/signature scheme than the default, run .Nm with the .Fl S Ar type option, where .Ar type is either .Cm RSA or .Cm DSA . The most frequent need to do this is when a .Cm DSA Ns -signed certificate is used. If it is necessary to use a different certificate scheme than the default, run .Nm with the .Fl c Ar scheme option and selected .Ar scheme as needed. If .Nm is run again without these options, it generates a new certificate using the same scheme and sign key, and soft link. .Pp After setting up the environment it is advisable to update certificates from time to time, if only to extend the validity interval. Simply run .Nm with the same flags as before to generate new certificates using existing keys, and soft links. However, if the host or sign key is changed, .Xr ntpd 1ntpdmdoc should be restarted. When .Xr ntpd 1ntpdmdoc is restarted, it loads any new files and restarts the protocol. Other dependent hosts will continue as usual until signatures are refreshed, at which time the protocol is restarted. .Ss Identity Schemes As mentioned on the Autonomous Authentication page, the default .Cm TC identity scheme is vulnerable to a middleman attack. However, there are more secure identity schemes available, including .Cm PC , IFF , GQ and .Cm MV schemes described below. These schemes are based on a TA, one or more trusted hosts and some number of nontrusted hosts. Trusted hosts prove identity using values provided by the TA, while the remaining hosts prove identity using values provided by a trusted host and certificate trails that end on that host. The name of a trusted host is also the name of its sugroup and also the subject and issuer name on its trusted certificate. The TA is not necessarily a trusted host in this sense, but often is. .Pp In some schemes there are separate keys for servers and clients. A server can also be a client of another server, but a client can never be a server for another client. In general, trusted hosts and nontrusted hosts that operate as both server and client have parameter files that contain both server and client keys. Hosts that operate only as clients have key files that contain only client keys. .Pp The PC scheme supports only one trusted host in the group. On trusted host alice run .Nm .Fl P .Fl p Ar password to generate the host key file .Pa ntpkey Ns _ Cm RSA Pa key_alice. Ar filestamp and trusted private certificate file .Pa ntpkey Ns _ Cm RSA-MD5 _ Pa cert_alice. Ar filestamp , and soft links. Copy both files to all group hosts; they replace the files which would be generated in other schemes. On each host .Ar bob install a soft link from the generic name .Pa ntpkey_host_ Ns Ar bob to the host key file and soft link .Pa ntpkey_cert_ Ns Ar bob to the private certificate file. Note the generic links are on bob, but point to files generated by trusted host alice. In this scheme it is not possible to refresh either the keys or certificates without copying them to all other hosts in the group, and recreating the soft links. .Pp For the .Cm IFF scheme proceed as in the .Cm TC scheme to generate keys and certificates for all group hosts, then for every trusted host in the group, generate the .Cm IFF parameter file. On trusted host alice run .Nm .Fl T .Fl I .Fl p Ar password to produce her parameter file .Pa ntpkey_IFFpar_alice. Ns Ar filestamp , which includes both server and client keys. Copy this file to all group hosts that operate as both servers and clients and install a soft link from the generic .Pa ntpkey_iff_alice to this file. If there are no hosts restricted to operate only as clients, there is nothing further to do. As the .Cm IFF scheme is independent of keys and certificates, these files can be refreshed as needed. .Pp If a rogue client has the parameter file, it could masquerade as a legitimate server and present a middleman threat. To eliminate this threat, the client keys can be extracted from the parameter file and distributed to all restricted clients. After generating the parameter file, on alice run .Nm .Fl e and pipe the output to a file or email program. Copy or email this file to all restricted clients. On these clients install a soft link from the generic .Pa ntpkey_iff_alice to this file. To further protect the integrity of the keys, each file can be encrypted with a secret password. .Pp For the .Cm GQ scheme proceed as in the .Cm TC scheme to generate keys and certificates for all group hosts, then for every trusted host in the group, generate the .Cm IFF parameter file. On trusted host alice run .Nm .Fl T .Fl G .Fl p Ar password to produce her parameter file .Pa ntpkey_GQpar_alice. Ns Ar filestamp , which includes both server and client keys. Copy this file to all group hosts and install a soft link from the generic .Pa ntpkey_gq_alice to this file. In addition, on each host .Ar bob install a soft link from generic .Pa ntpkey_gq_ Ns Ar bob to this file. As the .Cm GQ scheme updates the .Cm GQ parameters file and certificate at the same time, keys and certificates can be regenerated as needed. .Pp For the .Cm MV scheme, proceed as in the .Cm TC scheme to generate keys and certificates for all group hosts. For illustration assume trish is the TA, alice one of several trusted hosts and bob one of her clients. On TA trish run .Nm .Fl V Ar n .Fl p Ar password , where .Ar n is the number of revokable keys (typically 5) to produce the parameter file .Pa ntpkeys_MVpar_trish. Ns Ar filestamp and client key files .Pa ntpkeys_MVkey Ns Ar d _ Pa trish. Ar filestamp where .Ar d is the key number (0 \&< .Ar d \&< .Ar n ) . Copy the parameter file to alice and install a soft link from the generic .Pa ntpkey_mv_alice to this file. Copy one of the client key files to alice for later distribution to her clients. It does not matter which client key file goes to alice, since they all work the same way. Alice copies the client key file to all of her clients. On client bob install a soft link from generic .Pa ntpkey_mvkey_bob to the client key file. As the .Cm MV scheme is independent of keys and certificates, these files can be refreshed as needed. .Ss Command Line Options .Bl -tag -width indent .It Fl b Fl -imbits Ns = Ar modulus Set the number of bits in the identity modulus for generating identity keys to .Ar modulus bits. The number of bits in the identity modulus defaults to 256, but can be set to values from 256 to 2048 (32 to 256 octets). Use the larger moduli with caution, as this can consume considerable computing resources and increases the size of authenticated packets. .It Fl c Fl -certificate Ns = Ar scheme Select certificate signature encryption/message digest scheme. The .Ar scheme can be one of the following: .Cm RSA-MD2 , RSA-MD5 , RSA-MDC2 , RSA-SHA , RSA-SHA1 , RSA-RIPEMD160 , DSA-SHA , or .Cm DSA-SHA1 . Note that .Cm RSA schemes must be used with an .Cm RSA sign key and .Cm DSA schemes must be used with a .Cm DSA sign key. The default without this option is .Cm RSA-MD5 . If compatibility with FIPS 140-2 is required, either the .Cm DSA-SHA or .Cm DSA-SHA1 scheme must be used. .It Fl C Fl -cipher Ns = Ar cipher Select the OpenSSL cipher to encrypt the files containing private keys. The default without this option is three-key triple DES in CBC mode, .Cm des-ede3-cbc . The .Ic openssl Fl h command provided with OpenSSL displays available ciphers. .It Fl d Fl -debug-level Increase debugging verbosity level. This option displays the cryptographic data produced in eye-friendly billboards. .It Fl D Fl -set-debug-level Ns = Ar level Set the debugging verbosity to .Ar level . This option displays the cryptographic data produced in eye-friendly billboards. .It Fl e Fl -id-key Write the .Cm IFF or .Cm GQ public parameters from the .Ar IFFkey or GQkey client keys file previously specified as unencrypted data to the standard output stream .Pa stdout . This is intended for automatic key distribution by email. .It Fl G Fl -gq-params Generate a new encrypted .Cm GQ parameters and key file for the Guillou-Quisquater (GQ) identity scheme. This option is mutually exclusive with the .Fl I and .Fl V options. .It Fl H Fl -host-key Generate a new encrypted .Cm RSA public/private host key file. .It Fl I Fl -iffkey Generate a new encrypted .Cm IFF key file for the Schnorr (IFF) identity scheme. This option is mutually exclusive with the .Fl G and Fl V options. .It Fl i Fl -ident Ns = Ar group Set the optional Autokey group name to .Ar group . This is used in the identity scheme parameter file names of .Cm IFF , GQ , and .Cm MV client parameters files. In that role, the default is the host name if no group is provided. The group name, if specified using .Fl i or .Fl s following an .Ql @@ character, is also used in certificate subject and issuer names in the form .Ar host @@ group and should match the group specified via .Ic crypto Cm ident or .Ic server Cm ident in the ntpd configuration file. .It Fl l Fl -lifetime Ns = Ar days Set the lifetime for certificate expiration to .Ar days . The default lifetime is one year (365 days). .It Fl m Fl -modulus Ns = Ar bits Set the number of bits in the prime modulus for generating files to .Ar bits . The modulus defaults to 512, but can be set from 256 to 2048 (32 to 256 octets). Use the larger moduli with caution, as this can consume considerable computing resources and increases the size of authenticated packets. .It Fl M Fl -md5key Generate a new symmetric keys file containing 10 .Cm MD5 keys, and if OpenSSL is available, 10 .Cm SHA keys. An .Cm MD5 key is a string of 20 random printable ASCII characters, while a .Cm SHA key is a string of 40 random hex digits. The file can be edited using a text editor to change the key type or key content. This option is mutually exclusive with all other options. .It Fl p Fl -password Ns = Ar passwd Set the password for reading and writing encrypted files to .Ar passwd . These include the host, sign and identify key files. By default, the password is the string returned by the Unix .Ic hostname command. .It Fl P Fl -pvt-cert Generate a new private certificate used by the .Cm PC identity scheme. By default, the program generates public certificates. Note: the PC identity scheme is not recommended for new installations. .It Fl q Fl -export-passwd Ns = Ar passwd Set the password for writing encrypted .Cm IFF , GQ and MV identity files redirected to .Pa stdout to .Ar passwd . In effect, these files are decrypted with the .Fl p password, then encrypted with the .Fl q password. By default, the password is the string returned by the Unix .Ic hostname command. .It Fl s Fl -subject-key Ns = Ar Oo host Oc Op @@ Ar group Specify the Autokey host name, where .Ar host is the optional host name and .Ar group is the optional group name. The host name, and if provided, group name are used in .Ar host @@ group form as certificate subject and issuer. Specifying .Fl s @@ Ar group is allowed, and results in leaving the host name unchanged, as with .Fl i Ar group . The group name, or if no group is provided, the host name are also used in the file names of .Cm IFF , GQ , and .Cm MV identity scheme client parameter files. If .Ar host is not specified, the default host name is the string returned by the Unix .Ic hostname command. .It Fl S Fl -sign-key Ns = Op Cm RSA | DSA Generate a new encrypted public/private sign key file of the specified type. By default, the sign key is the host key and has the same type. If compatibility with FIPS 140-2 is required, the sign key type must be .Cm DSA . .It Fl T Fl -trusted-cert Generate a trusted certificate. By default, the program generates a non-trusted certificate. .It Fl V Fl -mv-params Ar nkeys Generate .Ar nkeys encrypted server keys and parameters for the Mu-Varadharajan (MV) identity scheme. This option is mutually exclusive with the .Fl I and .Fl G options. Note: support for this option should be considered a work in progress. .El .Ss Random Seed File All cryptographically sound key generation schemes must have means to randomize the entropy seed used to initialize the internal pseudo-random number generator used by the library routines. The OpenSSL library uses a designated random seed file for this purpose. The file must be available when starting the NTP daemon and .Nm program. If a site supports OpenSSL or its companion OpenSSH, it is very likely that means to do this are already available. .Pp It is important to understand that entropy must be evolved for each generation, for otherwise the random number sequence would be predictable. Various means dependent on external events, such as keystroke intervals, can be used to do this and some systems have built-in entropy sources. Suitable means are described in the OpenSSL software documentation, but are outside the scope of this page. .Pp The entropy seed used by the OpenSSL library is contained in a file, usually called .Pa .rnd , which must be available when starting the NTP daemon or the .Nm program. The NTP daemon will first look for the file using the path specified by the .Cm randfile subcommand of the .Ic crypto configuration command. If not specified in this way, or when starting the .Nm program, the OpenSSL library will look for the file using the path specified by the .Ev RANDFILE environment variable in the user home directory, whether root or some other user. If the .Ev RANDFILE environment variable is not present, the library will look for the .Pa .rnd file in the user home directory. Since both the .Nm program and .Xr ntpd 1ntpdmdoc daemon must run as root, the logical place to put this file is in .Pa /.rnd or .Pa /root/.rnd . If the file is not available or cannot be written, the daemon exits with a message to the system log and the program exits with a suitable error message. .Ss Cryptographic Data Files All file formats begin with two nonencrypted lines. The first line contains the file name, including the generated host name and filestamp, in the format .Pa ntpkey_ Ns Ar key _ Ar name . Ar filestamp , where .Ar key is the key or parameter type, .Ar name is the host or group name and .Ar filestamp is the filestamp (NTP seconds) when the file was created. By convention, .Ar key names in generated file names include both upper and lower case characters, while .Ar key names in generated link names include only lower case characters. The filestamp is not used in generated link names. The second line contains the datestamp in conventional Unix .Pa date format. Lines beginning with .Ql # are considered comments and ignored by the .Nm program and .Xr ntpd 1ntpdmdoc daemon. .Pp The remainder of the file contains cryptographic data, encoded first using ASN.1 rules, then encrypted if necessary, and finally written in PEM-encoded printable ASCII text, preceded and followed by MIME content identifier lines. .Pp The format of the symmetric keys file, ordinarily named .Pa ntp.keys , is somewhat different than the other files in the interest of backward compatibility. Ordinarily, the file is generated by this program, but it can be constructed and edited using an ordinary text editor. .Bd -literal -unfilled -offset center # ntpkey_MD5key_bk.ntp.org.3595864945 # Thu Dec 12 19:22:25 2013 1 MD5 L";Nw<\`.Il0%XXK9O'51VwVl0%XXK9O'51VwV MV parameters. This option takes an integer number as its argument. .sp Generate parameters and keys for the Mu\-Varadharajan (MV) identification scheme. .It Fl v Ar num , Fl \-mv\-keys Ns = Ns Ar num update MV keys. This option takes an integer number as its argument. .sp This option has not been fully documented. .It Fl \&? , Fl \-help Display usage information and exit. .It Fl \&! , Fl \-more\-help Pass the extended usage information through a pager. .It Fl > Oo Ar cfgfile Oc , Fl \-save\-opts Oo Ns = Ns Ar cfgfile Oc Save the option state to \fIcfgfile\fP. The default is the \fIlast\fP configuration file listed in the \fBOPTION PRESETS\fP section, below. The command will exit after updating the config file. .It Fl < Ar cfgfile , Fl \-load\-opts Ns = Ns Ar cfgfile , Fl \-no\-load\-opts Load options from \fIcfgfile\fP. The \fIno\-load\-opts\fP form will disable the loading of earlier config/rc/ini files. \fI\-\-no\-load\-opts\fP is handled early, out of order. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from configuration ("RC" or ".INI") file(s) and values from environment variables named: .nf \fBNTP_KEYGEN_\fP or \fBNTP_KEYGEN\fP .fi .ad The environmental presets take precedence (are processed later than) the configuration files. The \fIhomerc\fP files are "\fI$HOME\fP", and "\fI.\fP". If any of these are directories, then the file \fI.ntprc\fP is searched for within those directories. .Sh USAGE .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh "FILES" See \fBOPTION PRESETS\fP for configuration files. .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 66 " (EX_NOINPUT)" A specified configuration file could not be loaded. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh "AUTHORS" The University of Delaware and Network Time Foundation .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh BUGS It can take quite a while to generate some cryptographic values. .Pp Please report bugs to http://bugs.ntp.org . .Pp Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh NOTES Portions of this document came from FreeBSD. .Pp This manual page was \fIAutoGen\fP\-erated from the \fBntp\-keygen\fP option definitions. diff --git a/usr.sbin/ntp/doc/ntp.conf.5 b/usr.sbin/ntp/doc/ntp.conf.5 index 9e23a2294c48..71fb7c668db2 100644 --- a/usr.sbin/ntp/doc/ntp.conf.5 +++ b/usr.sbin/ntp/doc/ntp.conf.5 @@ -1,3277 +1,3277 @@ .Dd August 14 2018 .Dt NTP_CONF 5 File Formats .Os .\" EDIT THIS FILE WITH CAUTION (ntp.mdoc) .\" .\" It has been AutoGen-ed August 14, 2018 at 08:29:15 AM by AutoGen 5.18.5 .\" From the definitions ntp.conf.def .\" and the template file agmdoc-cmd.tpl .Sh NAME .Nm ntp.conf -.Nd Network Time Protocol (NTP) daemon configuration file format +.Nd Network Time Protocol daemon (ntpd) configuration format .Sh SYNOPSIS .Nm .Op Fl \-option\-name .Op Fl \-option\-name Ar value .Pp All arguments must be options. .Pp .Sh DESCRIPTION The .Nm configuration file is read at initial startup by the .Xr ntpd 8 daemon in order to specify the synchronization sources, modes and other related information. Usually, it is installed in the .Pa /etc directory, but could be installed elsewhere (see the daemon's .Fl c command line option). .Pp The file format is similar to other .Ux configuration files. Comments begin with a .Ql # character and extend to the end of the line; blank lines are ignored. Configuration commands consist of an initial keyword followed by a list of arguments, some of which may be optional, separated by whitespace. Commands may not be continued over multiple lines. Arguments may be host names, host addresses written in numeric, dotted\-quad form, integers, floating point numbers (when specifying times in seconds) and text strings. .Pp The rest of this page describes the configuration and control options. The .Qq Notes on Configuring NTP and Setting up an NTP Subnet page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) contains an extended discussion of these options. In addition to the discussion of general .Sx Configuration Options , there are sections describing the following supported functionality and the options used to control it: .Bl -bullet -offset indent .It .Sx Authentication Support .It .Sx Monitoring Support .It .Sx Access Control Support .It .Sx Automatic NTP Configuration Options .It .Sx Reference Clock Support .It .Sx Miscellaneous Options .El .Pp Following these is a section describing .Sx Miscellaneous Options . While there is a rich set of options available, the only required option is one or more .Ic pool , .Ic server , .Ic peer , .Ic broadcast or .Ic manycastclient commands. .Sh Configuration Support Following is a description of the configuration commands in NTPv4. These commands have the same basic functions as in NTPv3 and in some cases new functions and new arguments. There are two classes of commands, configuration commands that configure a persistent association with a remote server or peer or reference clock, and auxiliary commands that specify environmental variables that control various related operations. .Ss Configuration Commands The various modes are determined by the command keyword and the type of the required IP address. Addresses are classed by type as (s) a remote server or peer (IPv4 class A, B and C), (b) the broadcast address of a local interface, (m) a multicast address (IPv4 class D), or (r) a reference clock address (127.127.x.x). Note that only those options applicable to each command are listed below. Use of options not listed may not be caught as an error, but may result in some weird and even destructive behavior. .Pp If the Basic Socket Interface Extensions for IPv6 (RFC\-2553) is detected, support for the IPv6 address family is generated in addition to the default support of the IPv4 address family. In a few cases, including the .Cm reslist billboard generated by .Xr ntpq 8 or .Xr ntpdc 8 , IPv6 addresses are automatically generated. IPv6 addresses can be identified by the presence of colons .Dq \&: in the address field. IPv6 addresses can be used almost everywhere where IPv4 addresses can be used, with the exception of reference clock addresses, which are always IPv4. .Pp Note that in contexts where a host name is expected, a .Fl 4 qualifier preceding the host name forces DNS resolution to the IPv4 namespace, while a .Fl 6 qualifier forces DNS resolution to the IPv6 namespace. See IPv6 references for the equivalent classes for that address family. .Bl -tag -width indent .It Xo Ic pool Ar address .Op Cm burst .Op Cm iburst .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Xc .It Xo Ic server Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm burst .Op Cm iburst .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm true .Xc .It Xo Ic peer Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm true .Op Cm xleave .Xc .It Xo Ic broadcast Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm ttl Ar ttl .Op Cm xleave .Xc .It Xo Ic manycastclient Ar address .Op Cm key Ar key \&| Cm autokey .Op Cm version Ar version .Op Cm prefer .Op Cm minpoll Ar minpoll .Op Cm maxpoll Ar maxpoll .Op Cm ttl Ar ttl .Xc .El .Pp These five commands specify the time server name or address to be used and the mode in which to operate. The .Ar address can be either a DNS name or an IP address in dotted\-quad notation. Additional information on association behavior can be found in the .Qq Association Management page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Bl -tag -width indent .It Ic pool For type s addresses, this command mobilizes a persistent client mode association with a number of remote servers. In this mode the local clock can synchronized to the remote server, but the remote server can never be synchronized to the local clock. .It Ic server For type s and r addresses, this command mobilizes a persistent client mode association with the specified remote server or local radio clock. In this mode the local clock can synchronized to the remote server, but the remote server can never be synchronized to the local clock. This command should .Em not be used for type b or m addresses. .It Ic peer For type s addresses (only), this command mobilizes a persistent symmetric\-active mode association with the specified remote peer. In this mode the local clock can be synchronized to the remote peer or the remote peer can be synchronized to the local clock. This is useful in a network of servers where, depending on various failure scenarios, either the local or remote peer may be the better source of time. This command should NOT be used for type b, m or r addresses. .It Ic broadcast For type b and m addresses (only), this command mobilizes a persistent broadcast mode association. Multiple commands can be used to specify multiple local broadcast interfaces (subnets) and/or multiple multicast groups. Note that local broadcast messages go only to the interface associated with the subnet specified, but multicast messages go to all interfaces. In broadcast mode the local server sends periodic broadcast messages to a client population at the .Ar address specified, which is usually the broadcast address on (one of) the local network(s) or a multicast address assigned to NTP. The IANA has assigned the multicast group address IPv4 224.0.1.1 and IPv6 ff05::101 (site local) exclusively to NTP, but other nonconflicting addresses can be used to contain the messages within administrative boundaries. Ordinarily, this specification applies only to the local server operating as a sender; for operation as a broadcast client, see the .Ic broadcastclient or .Ic multicastclient commands below. .It Ic manycastclient For type m addresses (only), this command mobilizes a manycast client mode association for the multicast address specified. In this case a specific address must be supplied which matches the address used on the .Ic manycastserver command for the designated manycast servers. The NTP multicast address 224.0.1.1 assigned by the IANA should NOT be used, unless specific means are taken to avoid spraying large areas of the Internet with these messages and causing a possibly massive implosion of replies at the sender. The .Ic manycastserver command specifies that the local server is to operate in client mode with the remote servers that are discovered as the result of broadcast/multicast messages. The client broadcasts a request message to the group address associated with the specified .Ar address and specifically enabled servers respond to these messages. The client selects the servers providing the best time and continues as with the .Ic server command. The remaining servers are discarded as if never heard. .El .Pp Options: .Bl -tag -width indent .It Cm autokey All packets sent to and received from the server or peer are to include authentication fields encrypted using the autokey scheme described in .Sx Authentication Options . .It Cm burst when the server is reachable, send a burst of eight packets instead of the usual one. The packet spacing is normally 2 s; however, the spacing between the first and second packets can be changed with the .Ic calldelay command to allow additional time for a modem or ISDN call to complete. This is designed to improve timekeeping quality with the .Ic server command and s addresses. .It Cm iburst When the server is unreachable, send a burst of eight packets instead of the usual one. The packet spacing is normally 2 s; however, the spacing between the first two packets can be changed with the .Ic calldelay command to allow additional time for a modem or ISDN call to complete. This is designed to speed the initial synchronization acquisition with the .Ic server command and s addresses and when .Xr ntpd 8 is started with the .Fl q option. .It Cm key Ar key All packets sent to and received from the server or peer are to include authentication fields encrypted using the specified .Ar key identifier with values from 1 to 65535, inclusive. The default is to include no encryption field. .It Cm minpoll Ar minpoll .It Cm maxpoll Ar maxpoll These options specify the minimum and maximum poll intervals for NTP messages, as a power of 2 in seconds The maximum poll interval defaults to 10 (1,024 s), but can be increased by the .Cm maxpoll option to an upper limit of 17 (36.4 h). The minimum poll interval defaults to 6 (64 s), but can be decreased by the .Cm minpoll option to a lower limit of 4 (16 s). .It Cm noselect Marks the server as unused, except for display purposes. The server is discarded by the selection algroithm. .It Cm preempt Says the association can be preempted. .It Cm true Marks the server as a truechimer. Use this option only for testing. .It Cm prefer Marks the server as preferred. All other things being equal, this host will be chosen for synchronization among a set of correctly operating hosts. See the .Qq Mitigation Rules and the prefer Keyword page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) for further information. .It Cm true Forces the association to always survive the selection and clustering algorithms. This option should almost certainly .Em only be used while testing an association. .It Cm ttl Ar ttl This option is used only with broadcast server and manycast client modes. It specifies the time\-to\-live .Ar ttl to use on broadcast server and multicast server and the maximum .Ar ttl for the expanding ring search with manycast client packets. Selection of the proper value, which defaults to 127, is something of a black art and should be coordinated with the network administrator. .It Cm version Ar version Specifies the version number to be used for outgoing NTP packets. Versions 1\-4 are the choices, with version 4 the default. .It Cm xleave Valid in .Cm peer and .Cm broadcast modes only, this flag enables interleave mode. .El .Ss Auxiliary Commands .Bl -tag -width indent .It Ic broadcastclient This command enables reception of broadcast server messages to any local interface (type b) address. Upon receiving a message for the first time, the broadcast client measures the nominal server propagation delay using a brief client/server exchange with the server, then enters the broadcast client mode, in which it synchronizes to succeeding broadcast messages. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric\-key or public\-key authentication as described in .Sx Authentication Options . .It Ic manycastserver Ar address ... This command enables reception of manycast client messages to the multicast group address(es) (type m) specified. At least one address is required, but the NTP multicast address 224.0.1.1 assigned by the IANA should NOT be used, unless specific means are taken to limit the span of the reply and avoid a possibly massive implosion at the original sender. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric\-key or public\-key authentication as described in .Sx Authentication Options . .It Ic multicastclient Ar address ... This command enables reception of multicast server messages to the multicast group address(es) (type m) specified. Upon receiving a message for the first time, the multicast client measures the nominal server propagation delay using a brief client/server exchange with the server, then enters the broadcast client mode, in which it synchronizes to succeeding multicast messages. Note that, in order to avoid accidental or malicious disruption in this mode, both the server and client should operate using symmetric\-key or public\-key authentication as described in .Sx Authentication Options . .It Ic mdnstries Ar number If we are participating in mDNS, after we have synched for the first time we attempt to register with the mDNS system. If that registration attempt fails, we try again at one minute intervals for up to .Ic mdnstries times. After all, .Ic ntpd may be starting before mDNS. The default value for .Ic mdnstries is 5. .El .Sh Authentication Support Authentication support allows the NTP client to verify that the server is in fact known and trusted and not an intruder intending accidentally or on purpose to masquerade as that server. The NTPv3 specification RFC\-1305 defines a scheme which provides cryptographic authentication of received NTP packets. Originally, this was done using the Data Encryption Standard (DES) algorithm operating in Cipher Block Chaining (CBC) mode, commonly called DES\-CBC. Subsequently, this was replaced by the RSA Message Digest 5 (MD5) algorithm using a private key, commonly called keyed\-MD5. Either algorithm computes a message digest, or one\-way hash, which can be used to verify the server has the correct private key and key identifier. .Pp NTPv4 retains the NTPv3 scheme, properly described as symmetric key cryptography and, in addition, provides a new Autokey scheme based on public key cryptography. Public key cryptography is generally considered more secure than symmetric key cryptography, since the security is based on a private value which is generated by each server and never revealed. With Autokey all key distribution and management functions involve only public values, which considerably simplifies key distribution and storage. Public key management is based on X.509 certificates, which can be provided by commercial services or produced by utility programs in the OpenSSL software library or the NTPv4 distribution. .Pp While the algorithms for symmetric key cryptography are included in the NTPv4 distribution, public key cryptography requires the OpenSSL software library to be installed before building the NTP distribution. Directions for doing that are on the Building and Installing the Distribution page. .Pp Authentication is configured separately for each association using the .Cm key or .Cm autokey subcommand on the .Ic peer , .Ic server , .Ic broadcast and .Ic manycastclient configuration commands as described in .Sx Configuration Options page. The authentication options described below specify the locations of the key files, if other than default, which symmetric keys are trusted and the interval between various operations, if other than default. .Pp Authentication is always enabled, although ineffective if not configured as described below. If a NTP packet arrives including a message authentication code (MAC), it is accepted only if it passes all cryptographic checks. The checks require correct key ID, key value and message digest. If the packet has been modified in any way or replayed by an intruder, it will fail one or more of these checks and be discarded. Furthermore, the Autokey scheme requires a preliminary protocol exchange to obtain the server certificate, verify its credentials and initialize the protocol .Pp The .Cm auth flag controls whether new associations or remote configuration commands require cryptographic authentication. This flag can be set or reset by the .Ic enable and .Ic disable commands and also by remote configuration commands sent by a .Xr ntpdc 8 program running on another machine. If this flag is enabled, which is the default case, new broadcast client and symmetric passive associations and remote configuration commands must be cryptographically authenticated using either symmetric key or public key cryptography. If this flag is disabled, these operations are effective even if not cryptographic authenticated. It should be understood that operating with the .Ic auth flag disabled invites a significant vulnerability where a rogue hacker can masquerade as a falseticker and seriously disrupt system timekeeping. It is important to note that this flag has no purpose other than to allow or disallow a new association in response to new broadcast and symmetric active messages and remote configuration commands and, in particular, the flag has no effect on the authentication process itself. .Pp An attractive alternative where multicast support is available is manycast mode, in which clients periodically troll for servers as described in the .Sx Automatic NTP Configuration Options page. Either symmetric key or public key cryptographic authentication can be used in this mode. The principle advantage of manycast mode is that potential servers need not be configured in advance, since the client finds them during regular operation, and the configuration files for all clients can be identical. .Pp The security model and protocol schemes for both symmetric key and public key cryptography are summarized below; further details are in the briefings, papers and reports at the NTP project page linked from .Li http://www.ntp.org/ . .Ss Symmetric\-Key Cryptography The original RFC\-1305 specification allows any one of possibly 65,535 keys, each distinguished by a 32\-bit key identifier, to authenticate an association. The servers and clients involved must agree on the key and key identifier to authenticate NTP packets. Keys and related information are specified in a key file, usually called .Pa ntp.keys , which must be distributed and stored using secure means beyond the scope of the NTP protocol itself. Besides the keys used for ordinary NTP associations, additional keys can be used as passwords for the .Xr ntpq 8 and .Xr ntpdc 8 utility programs. .Pp When .Xr ntpd 8 is first started, it reads the key file specified in the .Ic keys configuration command and installs the keys in the key cache. However, individual keys must be activated with the .Ic trusted command before use. This allows, for instance, the installation of possibly several batches of keys and then activating or deactivating each batch remotely using .Xr ntpdc 8 . This also provides a revocation capability that can be used if a key becomes compromised. The .Ic requestkey command selects the key used as the password for the .Xr ntpdc 8 utility, while the .Ic controlkey command selects the key used as the password for the .Xr ntpq 8 utility. .Ss Public Key Cryptography NTPv4 supports the original NTPv3 symmetric key scheme described in RFC\-1305 and in addition the Autokey protocol, which is based on public key cryptography. The Autokey Version 2 protocol described on the Autokey Protocol page verifies packet integrity using MD5 message digests and verifies the source with digital signatures and any of several digest/signature schemes. Optional identity schemes described on the Identity Schemes page and based on cryptographic challenge/response algorithms are also available. Using all of these schemes provides strong security against replay with or without modification, spoofing, masquerade and most forms of clogging attacks. .\" .Pp .\" The cryptographic means necessary for all Autokey operations .\" is provided by the OpenSSL software library. .\" This library is available from http://www.openssl.org/ .\" and can be installed using the procedures outlined .\" in the Building and Installing the Distribution page. .\" Once installed, .\" the configure and build .\" process automatically detects the library and links .\" the library routines required. .Pp The Autokey protocol has several modes of operation corresponding to the various NTP modes supported. Most modes use a special cookie which can be computed independently by the client and server, but encrypted in transmission. All modes use in addition a variant of the S\-KEY scheme, in which a pseudo\-random key list is generated and used in reverse order. These schemes are described along with an executive summary, current status, briefing slides and reading list on the .Sx Autonomous Authentication page. .Pp The specific cryptographic environment used by Autokey servers and clients is determined by a set of files and soft links generated by the .Xr ntp\-keygen 1ntpkeygenmdoc program. This includes a required host key file, required certificate file and optional sign key file, leapsecond file and identity scheme files. The digest/signature scheme is specified in the X.509 certificate along with the matching sign key. There are several schemes available in the OpenSSL software library, each identified by a specific string such as .Cm md5WithRSAEncryption , which stands for the MD5 message digest with RSA encryption scheme. The current NTP distribution supports all the schemes in the OpenSSL library, including those based on RSA and DSA digital signatures. .Pp NTP secure groups can be used to define cryptographic compartments and security hierarchies. It is important that every host in the group be able to construct a certificate trail to one or more trusted hosts in the same group. Each group host runs the Autokey protocol to obtain the certificates for all hosts along the trail to one or more trusted hosts. This requires the configuration file in all hosts to be engineered so that, even under anticipated failure conditions, the NTP subnet will form such that every group host can find a trail to at least one trusted host. .Ss Naming and Addressing It is important to note that Autokey does not use DNS to resolve addresses, since DNS can't be completely trusted until the name servers have synchronized clocks. The cryptographic name used by Autokey to bind the host identity credentials and cryptographic values must be independent of interface, network and any other naming convention. The name appears in the host certificate in either or both the subject and issuer fields, so protection against DNS compromise is essential. .Pp By convention, the name of an Autokey host is the name returned by the Unix .Xr gethostname 2 system call or equivalent in other systems. By the system design model, there are no provisions to allow alternate names or aliases. However, this is not to say that DNS aliases, different names for each interface, etc., are constrained in any way. .Pp It is also important to note that Autokey verifies authenticity using the host name, network address and public keys, all of which are bound together by the protocol specifically to deflect masquerade attacks. For this reason Autokey includes the source and destination IP addresses in message digest computations and so the same addresses must be available at both the server and client. For this reason operation with network address translation schemes is not possible. This reflects the intended robust security model where government and corporate NTP servers are operated outside firewall perimeters. .Ss Operation A specific combination of authentication scheme (none, symmetric key, public key) and identity scheme is called a cryptotype, although not all combinations are compatible. There may be management configurations where the clients, servers and peers may not all support the same cryptotypes. A secure NTPv4 subnet can be configured in many ways while keeping in mind the principles explained above and in this section. Note however that some cryptotype combinations may successfully interoperate with each other, but may not represent good security practice. .Pp The cryptotype of an association is determined at the time of mobilization, either at configuration time or some time later when a message of appropriate cryptotype arrives. When mobilized by a .Ic server or .Ic peer configuration command and no .Ic key or .Ic autokey subcommands are present, the association is not authenticated; if the .Ic key subcommand is present, the association is authenticated using the symmetric key ID specified; if the .Ic autokey subcommand is present, the association is authenticated using Autokey. .Pp When multiple identity schemes are supported in the Autokey protocol, the first message exchange determines which one is used. The client request message contains bits corresponding to which schemes it has available. The server response message contains bits corresponding to which schemes it has available. Both server and client match the received bits with their own and select a common scheme. .Pp Following the principle that time is a public value, a server responds to any client packet that matches its cryptotype capabilities. Thus, a server receiving an unauthenticated packet will respond with an unauthenticated packet, while the same server receiving a packet of a cryptotype it supports will respond with packets of that cryptotype. However, unconfigured broadcast or manycast client associations or symmetric passive associations will not be mobilized unless the server supports a cryptotype compatible with the first packet received. By default, unauthenticated associations will not be mobilized unless overridden in a decidedly dangerous way. .Pp Some examples may help to reduce confusion. Client Alice has no specific cryptotype selected. Server Bob has both a symmetric key file and minimal Autokey files. Alice's unauthenticated messages arrive at Bob, who replies with unauthenticated messages. Cathy has a copy of Bob's symmetric key file and has selected key ID 4 in messages to Bob. Bob verifies the message with his key ID 4. If it's the same key and the message is verified, Bob sends Cathy a reply authenticated with that key. If verification fails, Bob sends Cathy a thing called a crypto\-NAK, which tells her something broke. She can see the evidence using the .Xr ntpq 8 program. .Pp Denise has rolled her own host key and certificate. She also uses one of the identity schemes as Bob. She sends the first Autokey message to Bob and they both dance the protocol authentication and identity steps. If all comes out okay, Denise and Bob continue as described above. .Pp It should be clear from the above that Bob can support all the girls at the same time, as long as he has compatible authentication and identity credentials. Now, Bob can act just like the girls in his own choice of servers; he can run multiple configured associations with multiple different servers (or the same server, although that might not be useful). But, wise security policy might preclude some cryptotype combinations; for instance, running an identity scheme with one server and no authentication with another might not be wise. .Ss Key Management The cryptographic values used by the Autokey protocol are incorporated as a set of files generated by the .Xr ntp\-keygen 1ntpkeygenmdoc utility program, including symmetric key, host key and public certificate files, as well as sign key, identity parameters and leapseconds files. Alternatively, host and sign keys and certificate files can be generated by the OpenSSL utilities and certificates can be imported from public certificate authorities. Note that symmetric keys are necessary for the .Xr ntpq 8 and .Xr ntpdc 8 utility programs. The remaining files are necessary only for the Autokey protocol. .Pp Certificates imported from OpenSSL or public certificate authorities have certain limitations. The certificate should be in ASN.1 syntax, X.509 Version 3 format and encoded in PEM, which is the same format used by OpenSSL. The overall length of the certificate encoded in ASN.1 must not exceed 1024 bytes. The subject distinguished name field (CN) is the fully qualified name of the host on which it is used; the remaining subject fields are ignored. The certificate extension fields must not contain either a subject key identifier or a issuer key identifier field; however, an extended key usage field for a trusted host must contain the value .Cm trustRoot ; . Other extension fields are ignored. .Ss Authentication Commands .Bl -tag -width indent .It Ic autokey Op Ar logsec Specifies the interval between regenerations of the session key list used with the Autokey protocol. Note that the size of the key list for each association depends on this interval and the current poll interval. The default value is 12 (4096 s or about 1.1 hours). For poll intervals above the specified interval, a session key list with a single entry will be regenerated for every message sent. .It Ic controlkey Ar key Specifies the key identifier to use with the .Xr ntpq 8 utility, which uses the standard protocol defined in RFC\-1305. The .Ar key argument is the key identifier for a trusted key, where the value can be in the range 1 to 65,535, inclusive. .It Xo Ic crypto .Op Cm cert Ar file .Op Cm leap Ar file .Op Cm randfile Ar file .Op Cm host Ar file .Op Cm sign Ar file .Op Cm gq Ar file .Op Cm gqpar Ar file .Op Cm iffpar Ar file .Op Cm mvpar Ar file .Op Cm pw Ar password .Xc This command requires the OpenSSL library. It activates public key cryptography, selects the message digest and signature encryption scheme and loads the required private and public values described above. If one or more files are left unspecified, the default names are used as described above. Unless the complete path and name of the file are specified, the location of a file is relative to the keys directory specified in the .Ic keysdir command or default .Pa /usr/local/etc . Following are the subcommands: .Bl -tag -width indent .It Cm cert Ar file Specifies the location of the required host public certificate file. This overrides the link .Pa ntpkey_cert_ Ns Ar hostname in the keys directory. .It Cm gqpar Ar file Specifies the location of the optional GQ parameters file. This overrides the link .Pa ntpkey_gq_ Ns Ar hostname in the keys directory. .It Cm host Ar file Specifies the location of the required host key file. This overrides the link .Pa ntpkey_key_ Ns Ar hostname in the keys directory. .It Cm iffpar Ar file Specifies the location of the optional IFF parameters file. This overrides the link .Pa ntpkey_iff_ Ns Ar hostname in the keys directory. .It Cm leap Ar file Specifies the location of the optional leapsecond file. This overrides the link .Pa ntpkey_leap in the keys directory. .It Cm mvpar Ar file Specifies the location of the optional MV parameters file. This overrides the link .Pa ntpkey_mv_ Ns Ar hostname in the keys directory. .It Cm pw Ar password Specifies the password to decrypt files containing private keys and identity parameters. This is required only if these files have been encrypted. .It Cm randfile Ar file Specifies the location of the random seed file used by the OpenSSL library. The defaults are described in the main text above. .It Cm sign Ar file Specifies the location of the optional sign key file. This overrides the link .Pa ntpkey_sign_ Ns Ar hostname in the keys directory. If this file is not found, the host key is also the sign key. .El .It Ic keys Ar keyfile Specifies the complete path and location of the MD5 key file containing the keys and key identifiers used by .Xr ntpd 8 , .Xr ntpq 8 and .Xr ntpdc 8 when operating with symmetric key cryptography. This is the same operation as the .Fl k command line option. .It Ic keysdir Ar path This command specifies the default directory path for cryptographic keys, parameters and certificates. The default is .Pa /usr/local/etc/ . .It Ic requestkey Ar key Specifies the key identifier to use with the .Xr ntpdc 8 utility program, which uses a proprietary protocol specific to this implementation of .Xr ntpd 8 . The .Ar key argument is a key identifier for the trusted key, where the value can be in the range 1 to 65,535, inclusive. .It Ic revoke Ar logsec Specifies the interval between re\-randomization of certain cryptographic values used by the Autokey scheme, as a power of 2 in seconds. These values need to be updated frequently in order to deflect brute\-force attacks on the algorithms of the scheme; however, updating some values is a relatively expensive operation. The default interval is 16 (65,536 s or about 18 hours). For poll intervals above the specified interval, the values will be updated for every message sent. .It Ic trustedkey Ar key ... Specifies the key identifiers which are trusted for the purposes of authenticating peers with symmetric key cryptography, as well as keys used by the .Xr ntpq 8 and .Xr ntpdc 8 programs. The authentication procedures require that both the local and remote servers share the same key and key identifier for this purpose, although different keys can be used with different servers. The .Ar key arguments are 32\-bit unsigned integers with values from 1 to 65,535. .El .Ss Error Codes The following error codes are reported via the NTP control and monitoring protocol trap mechanism. .Bl -tag -width indent .It 101 .Pq bad field format or length The packet has invalid version, length or format. .It 102 .Pq bad timestamp The packet timestamp is the same or older than the most recent received. This could be due to a replay or a server clock time step. .It 103 .Pq bad filestamp The packet filestamp is the same or older than the most recent received. This could be due to a replay or a key file generation error. .It 104 .Pq bad or missing public key The public key is missing, has incorrect format or is an unsupported type. .It 105 .Pq unsupported digest type The server requires an unsupported digest/signature scheme. .It 106 .Pq mismatched digest types Not used. .It 107 .Pq bad signature length The signature length does not match the current public key. .It 108 .Pq signature not verified The message fails the signature check. It could be bogus or signed by a different private key. .It 109 .Pq certificate not verified The certificate is invalid or signed with the wrong key. .It 110 .Pq certificate not verified The certificate is not yet valid or has expired or the signature could not be verified. .It 111 .Pq bad or missing cookie The cookie is missing, corrupted or bogus. .It 112 .Pq bad or missing leapseconds table The leapseconds table is missing, corrupted or bogus. .It 113 .Pq bad or missing certificate The certificate is missing, corrupted or bogus. .It 114 .Pq bad or missing identity The identity key is missing, corrupt or bogus. .El .Sh Monitoring Support .Xr ntpd 8 includes a comprehensive monitoring facility suitable for continuous, long term recording of server and client timekeeping performance. See the .Ic statistics command below for a listing and example of each type of statistics currently supported. Statistic files are managed using file generation sets and scripts in the .Pa ./scripts directory of the source code distribution. Using these facilities and .Ux .Xr cron 8 jobs, the data can be automatically summarized and archived for retrospective analysis. .Ss Monitoring Commands .Bl -tag -width indent .It Ic statistics Ar name ... Enables writing of statistics records. Currently, eight kinds of .Ar name statistics are supported. .Bl -tag -width indent .It Cm clockstats Enables recording of clock driver statistics information. Each update received from a clock driver appends a line of the following form to the file generation set named .Cm clockstats : .Bd -literal 49213 525.624 127.127.4.1 93 226 00:08:29.606 D .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next field shows the clock address in dotted\-quad notation. The final field shows the last timecode received from the clock in decoded ASCII format, where meaningful. In some clock drivers a good deal of additional information can be gathered and displayed as well. See information specific to each clock for further details. .It Cm cryptostats This option requires the OpenSSL cryptographic software library. It enables recording of cryptographic public key protocol information. Each message received by the protocol module appends a line of the following form to the file generation set named .Cm cryptostats : .Bd -literal 49213 525.624 127.127.4.1 message .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next field shows the peer address in dotted\-quad notation, The final message field includes the message type and certain ancillary information. See the .Sx Authentication Options section for further information. .It Cm loopstats Enables recording of loop filter statistics information. Each update of the local clock outputs a line of the following form to the file generation set named .Cm loopstats : .Bd -literal 50935 75440.031 0.000006019 13.778190 0.000351733 0.0133806 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next five fields show time offset (seconds), frequency offset (parts per million \- PPM), RMS jitter (seconds), Allan deviation (PPM) and clock discipline time constant. .It Cm peerstats Enables recording of peer statistics information. This includes statistics records of all peers of a NTP server and of special signals, where present and configured. Each valid update appends a line of the following form to the current element of a file generation set named .Cm peerstats : .Bd -literal 48773 10847.650 127.127.4.1 9714 \-0.001605376 0.000000000 0.001424877 0.000958674 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next two fields show the peer address in dotted\-quad notation and status, respectively. The status field is encoded in hex in the format described in Appendix A of the NTP specification RFC 1305. The final four fields show the offset, delay, dispersion and RMS jitter, all in seconds. .It Cm rawstats Enables recording of raw\-timestamp statistics information. This includes statistics records of all peers of a NTP server and of special signals, where present and configured. Each NTP message received from a peer or clock driver appends a line of the following form to the file generation set named .Cm rawstats : .Bd -literal 50928 2132.543 128.4.1.1 128.4.1.20 3102453281.584327000 3102453281.58622800031 02453332.540806000 3102453332.541458000 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The next two fields show the remote peer or clock address followed by the local address in dotted\-quad notation. The final four fields show the originate, receive, transmit and final NTP timestamps in order. The timestamp values are as received and before processing by the various data smoothing and mitigation algorithms. .It Cm sysstats Enables recording of ntpd statistics counters on a periodic basis. Each hour a line of the following form is appended to the file generation set named .Cm sysstats : .Bd -literal 50928 2132.543 36000 81965 0 9546 56 71793 512 540 10 147 .Ed .Pp The first two fields show the date (Modified Julian Day) and time (seconds and fraction past UTC midnight). The remaining ten fields show the statistics counter values accumulated since the last generated line. .Bl -tag -width indent .It Time since restart Cm 36000 Time in hours since the system was last rebooted. .It Packets received Cm 81965 Total number of packets received. .It Packets processed Cm 0 Number of packets received in response to previous packets sent .It Current version Cm 9546 Number of packets matching the current NTP version. .It Previous version Cm 56 Number of packets matching the previous NTP version. .It Bad version Cm 71793 Number of packets matching neither NTP version. .It Access denied Cm 512 Number of packets denied access for any reason. .It Bad length or format Cm 540 Number of packets with invalid length, format or port number. .It Bad authentication Cm 10 Number of packets not verified as authentic. .It Rate exceeded Cm 147 Number of packets discarded due to rate limitation. .El .It Cm statsdir Ar directory_path Indicates the full path of a directory where statistics files should be created (see below). This keyword allows the (otherwise constant) .Cm filegen filename prefix to be modified for file generation sets, which is useful for handling statistics logs. .It Cm filegen Ar name Xo .Op Cm file Ar filename .Op Cm type Ar typename .Op Cm link | nolink .Op Cm enable | disable .Xc Configures setting of generation file set name. Generation file sets provide a means for handling files that are continuously growing during the lifetime of a server. Server statistics are a typical example for such files. Generation file sets provide access to a set of files used to store the actual data. At any time at most one element of the set is being written to. The type given specifies when and how data will be directed to a new element of the set. This way, information stored in elements of a file set that are currently unused are available for administrational operations without the risk of disturbing the operation of ntpd. (Most important: they can be removed to free space for new data produced.) .Pp Note that this command can be sent from the .Xr ntpdc 8 program running at a remote location. .Bl -tag -width indent .It Cm name This is the type of the statistics records, as shown in the .Cm statistics command. .It Cm file Ar filename This is the file name for the statistics records. Filenames of set members are built from three concatenated elements .Ar Cm prefix , .Ar Cm filename and .Ar Cm suffix : .Bl -tag -width indent .It Cm prefix This is a constant filename path. It is not subject to modifications via the .Ar filegen option. It is defined by the server, usually specified as a compile\-time constant. It may, however, be configurable for individual file generation sets via other commands. For example, the prefix used with .Ar loopstats and .Ar peerstats generation can be configured using the .Ar statsdir option explained above. .It Cm filename This string is directly concatenated to the prefix mentioned above (no intervening .Ql / ) . This can be modified using the file argument to the .Ar filegen statement. No .Pa .. elements are allowed in this component to prevent filenames referring to parts outside the filesystem hierarchy denoted by .Ar prefix . .It Cm suffix This part is reflects individual elements of a file set. It is generated according to the type of a file set. .El .It Cm type Ar typename A file generation set is characterized by its type. The following types are supported: .Bl -tag -width indent .It Cm none The file set is actually a single plain file. .It Cm pid One element of file set is used per incarnation of a ntpd server. This type does not perform any changes to file set members during runtime, however it provides an easy way of separating files belonging to different .Xr ntpd 8 server incarnations. The set member filename is built by appending a .Ql \&. to concatenated .Ar prefix and .Ar filename strings, and appending the decimal representation of the process ID of the .Xr ntpd 8 server process. .It Cm day One file generation set element is created per day. A day is defined as the period between 00:00 and 24:00 UTC. The file set member suffix consists of a .Ql \&. and a day specification in the form .Cm YYYYMMdd . .Cm YYYY is a 4\-digit year number (e.g., 1992). .Cm MM is a two digit month number. .Cm dd is a two digit day number. Thus, all information written at 10 December 1992 would end up in a file named .Ar prefix .Ar filename Ns .19921210 . .It Cm week Any file set member contains data related to a certain week of a year. The term week is defined by computing day\-of\-year modulo 7. Elements of such a file generation set are distinguished by appending the following suffix to the file set filename base: A dot, a 4\-digit year number, the letter .Cm W , and a 2\-digit week number. For example, information from January, 10th 1992 would end up in a file with suffix .No . Ns Ar 1992W1 . .It Cm month One generation file set element is generated per month. The file name suffix consists of a dot, a 4\-digit year number, and a 2\-digit month. .It Cm year One generation file element is generated per year. The filename suffix consists of a dot and a 4 digit year number. .It Cm age This type of file generation sets changes to a new element of the file set every 24 hours of server operation. The filename suffix consists of a dot, the letter .Cm a , and an 8\-digit number. This number is taken to be the number of seconds the server is running at the start of the corresponding 24\-hour period. Information is only written to a file generation by specifying .Cm enable ; output is prevented by specifying .Cm disable . .El .It Cm link | nolink It is convenient to be able to access the current element of a file generation set by a fixed name. This feature is enabled by specifying .Cm link and disabled using .Cm nolink . If link is specified, a hard link from the current file set element to a file without suffix is created. When there is already a file with this name and the number of links of this file is one, it is renamed appending a dot, the letter .Cm C , and the pid of the .Xr ntpd 8 server process. When the number of links is greater than one, the file is unlinked. This allows the current file to be accessed by a constant name. .It Cm enable \&| Cm disable Enables or disables the recording function. .El .El .El .Sh Access Control Support The .Xr ntpd 8 daemon implements a general purpose address/mask based restriction list. The list contains address/match entries sorted first by increasing address values and and then by increasing mask values. A match occurs when the bitwise AND of the mask and the packet source address is equal to the bitwise AND of the mask and address in the list. The list is searched in order with the last match found defining the restriction flags associated with the entry. Additional information and examples can be found in the .Qq Notes on Configuring NTP and Setting up a NTP Subnet page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Pp The restriction facility was implemented in conformance with the access policies for the original NSFnet backbone time servers. Later the facility was expanded to deflect cryptographic and clogging attacks. While this facility may be useful for keeping unwanted or broken or malicious clients from congesting innocent servers, it should not be considered an alternative to the NTP authentication facilities. Source address based restrictions are easily circumvented by a determined cracker. .Pp Clients can be denied service because they are explicitly included in the restrict list created by the .Ic restrict command or implicitly as the result of cryptographic or rate limit violations. Cryptographic violations include certificate or identity verification failure; rate limit violations generally result from defective NTP implementations that send packets at abusive rates. Some violations cause denied service only for the offending packet, others cause denied service for a timed period and others cause the denied service for an indefinite period. When a client or network is denied access for an indefinite period, the only way at present to remove the restrictions is by restarting the server. .Ss The Kiss\-of\-Death Packet Ordinarily, packets denied service are simply dropped with no further action except incrementing statistics counters. Sometimes a more proactive response is needed, such as a server message that explicitly requests the client to stop sending and leave a message for the system operator. A special packet format has been created for this purpose called the "kiss\-of\-death" (KoD) packet. KoD packets have the leap bits set unsynchronized and stratum set to zero and the reference identifier field set to a four\-byte ASCII code. If the .Cm noserve or .Cm notrust flag of the matching restrict list entry is set, the code is "DENY"; if the .Cm limited flag is set and the rate limit is exceeded, the code is "RATE". Finally, if a cryptographic violation occurs, the code is "CRYP". .Pp A client receiving a KoD performs a set of sanity checks to minimize security exposure, then updates the stratum and reference identifier peer variables, sets the access denied (TEST4) bit in the peer flash variable and sends a message to the log. As long as the TEST4 bit is set, the client will send no further packets to the server. The only way at present to recover from this condition is to restart the protocol at both the client and server. This happens automatically at the client when the association times out. It will happen at the server only if the server operator cooperates. .Ss Access Control Commands .Bl -tag -width indent .It Xo Ic discard .Op Cm average Ar avg .Op Cm minimum Ar min .Op Cm monitor Ar prob .Xc Set the parameters of the .Cm limited facility which protects the server from client abuse. The .Cm average subcommand specifies the minimum average packet spacing, while the .Cm minimum subcommand specifies the minimum packet spacing. Packets that violate these minima are discarded and a kiss\-o'\-death packet returned if enabled. The default minimum average and minimum are 5 and 2, respectively. The .Ic monitor subcommand specifies the probability of discard for packets that overflow the rate\-control window. .It Xo Ic restrict address .Op Cm mask Ar mask .Op Cm ippeerlimit Ar int .Op Ar flag ... .Xc The .Ar address argument expressed in dotted\-quad form is the address of a host or network. Alternatively, the .Ar address argument can be a valid host DNS name. The .Ar mask argument expressed in dotted\-quad form defaults to .Cm 255.255.255.255 , meaning that the .Ar address is treated as the address of an individual host. A default entry (address .Cm 0.0.0.0 , mask .Cm 0.0.0.0 ) is always included and is always the first entry in the list. Note that text string .Cm default , with no mask option, may be used to indicate the default entry. The .Cm ippeerlimit directive limits the number of peer requests for each IP to .Ar int , where a value of \-1 means "unlimited", the current default. A value of 0 means "none". There would usually be at most 1 peering request per IP, but if the remote peering requests are behind a proxy there could well be more than 1 per IP. In the current implementation, .Cm flag always restricts access, i.e., an entry with no flags indicates that free access to the server is to be given. The flags are not orthogonal, in that more restrictive flags will often make less restrictive ones redundant. The flags can generally be classed into two categories, those which restrict time service and those which restrict informational queries and attempts to do run\-time reconfiguration of the server. One or more of the following flags may be specified: .Bl -tag -width indent .It Cm ignore Deny packets of all kinds, including .Xr ntpq 8 and .Xr ntpdc 8 queries. .It Cm kod If this flag is set when an access violation occurs, a kiss\-o'\-death (KoD) packet is sent. KoD packets are rate limited to no more than one per second. If another KoD packet occurs within one second after the last one, the packet is dropped. .It Cm limited Deny service if the packet spacing violates the lower limits specified in the .Ic discard command. A history of clients is kept using the monitoring capability of .Xr ntpd 8 . Thus, monitoring is always active as long as there is a restriction entry with the .Cm limited flag. .It Cm lowpriotrap Declare traps set by matching hosts to be low priority. The number of traps a server can maintain is limited (the current limit is 3). Traps are usually assigned on a first come, first served basis, with later trap requestors being denied service. This flag modifies the assignment algorithm by allowing low priority traps to be overridden by later requests for normal priority traps. .It Cm noepeer Deny ephemeral peer requests, even if they come from an authenticated source. Note that the ability to use a symmetric key for authentication may be restricted to one or more IPs or subnets via the third field of the .Pa ntp.keys file. This restriction is not enabled by default, to maintain backward compatibility. Expect .Cm noepeer to become the default in ntp\-4.4. .It Cm nomodify Deny .Xr ntpq 8 and .Xr ntpdc 8 queries which attempt to modify the state of the server (i.e., run time reconfiguration). Queries which return information are permitted. .It Cm noquery Deny .Xr ntpq 8 and .Xr ntpdc 8 queries. Time service is not affected. .It Cm nopeer Deny unauthenticated packets which would result in mobilizing a new association. This includes broadcast and symmetric active packets when a configured association does not exist. It also includes .Cm pool associations, so if you want to use servers from a .Cm pool directive and also want to use .Cm nopeer by default, you'll want a .Cm "restrict source ..." line as well that does .Em not include the .Cm nopeer directive. .It Cm noserve Deny all packets except .Xr ntpq 8 and .Xr ntpdc 8 queries. .It Cm notrap Decline to provide mode 6 control message trap service to matching hosts. The trap service is a subsystem of the .Xr ntpq 8 control message protocol which is intended for use by remote event logging programs. .It Cm notrust Deny service unless the packet is cryptographically authenticated. .It Cm ntpport This is actually a match algorithm modifier, rather than a restriction flag. Its presence causes the restriction entry to be matched only if the source port in the packet is the standard NTP UDP port (123). Both .Cm ntpport and .Cm non\-ntpport may be specified. The .Cm ntpport is considered more specific and is sorted later in the list. .It Cm version Deny packets that do not match the current NTP version. .El .Pp Default restriction list entries with the flags ignore, interface, ntpport, for each of the local host's interface addresses are inserted into the table at startup to prevent the server from attempting to synchronize to its own time. A default entry is also always present, though if it is otherwise unconfigured; no flags are associated with the default entry (i.e., everything besides your own NTP server is unrestricted). .El .Sh Automatic NTP Configuration Options .Ss Manycasting Manycasting is a automatic discovery and configuration paradigm new to NTPv4. It is intended as a means for a multicast client to troll the nearby network neighborhood to find cooperating manycast servers, validate them using cryptographic means and evaluate their time values with respect to other servers that might be lurking in the vicinity. The intended result is that each manycast client mobilizes client associations with some number of the "best" of the nearby manycast servers, yet automatically reconfigures to sustain this number of servers should one or another fail. .Pp Note that the manycasting paradigm does not coincide with the anycast paradigm described in RFC\-1546, which is designed to find a single server from a clique of servers providing the same service. The manycast paradigm is designed to find a plurality of redundant servers satisfying defined optimality criteria. .Pp Manycasting can be used with either symmetric key or public key cryptography. The public key infrastructure (PKI) offers the best protection against compromised keys and is generally considered stronger, at least with relatively large key sizes. It is implemented using the Autokey protocol and the OpenSSL cryptographic library available from .Li http://www.openssl.org/ . The library can also be used with other NTPv4 modes as well and is highly recommended, especially for broadcast modes. .Pp A persistent manycast client association is configured using the .Ic manycastclient command, which is similar to the .Ic server command but with a multicast (IPv4 class .Cm D or IPv6 prefix .Cm FF ) group address. The IANA has designated IPv4 address 224.1.1.1 and IPv6 address FF05::101 (site local) for NTP. When more servers are needed, it broadcasts manycast client messages to this address at the minimum feasible rate and minimum feasible time\-to\-live (TTL) hops, depending on how many servers have already been found. There can be as many manycast client associations as different group address, each one serving as a template for a future ephemeral unicast client/server association. .Pp Manycast servers configured with the .Ic manycastserver command listen on the specified group address for manycast client messages. Note the distinction between manycast client, which actively broadcasts messages, and manycast server, which passively responds to them. If a manycast server is in scope of the current TTL and is itself synchronized to a valid source and operating at a stratum level equal to or lower than the manycast client, it replies to the manycast client message with an ordinary unicast server message. .Pp The manycast client receiving this message mobilizes an ephemeral client/server association according to the matching manycast client template, but only if cryptographically authenticated and the server stratum is less than or equal to the client stratum. Authentication is explicitly required and either symmetric key or public key (Autokey) can be used. Then, the client polls the server at its unicast address in burst mode in order to reliably set the host clock and validate the source. This normally results in a volley of eight client/server at 2\-s intervals during which both the synchronization and cryptographic protocols run concurrently. Following the volley, the client runs the NTP intersection and clustering algorithms, which act to discard all but the "best" associations according to stratum and synchronization distance. The surviving associations then continue in ordinary client/server mode. .Pp The manycast client polling strategy is designed to reduce as much as possible the volume of manycast client messages and the effects of implosion due to near\-simultaneous arrival of manycast server messages. The strategy is determined by the .Ic manycastclient , .Ic tos and .Ic ttl configuration commands. The manycast poll interval is normally eight times the system poll interval, which starts out at the .Cm minpoll value specified in the .Ic manycastclient , command and, under normal circumstances, increments to the .Cm maxpolll value specified in this command. Initially, the TTL is set at the minimum hops specified by the .Ic ttl command. At each retransmission the TTL is increased until reaching the maximum hops specified by this command or a sufficient number client associations have been found. Further retransmissions use the same TTL. .Pp The quality and reliability of the suite of associations discovered by the manycast client is determined by the NTP mitigation algorithms and the .Cm minclock and .Cm minsane values specified in the .Ic tos configuration command. At least .Cm minsane candidate servers must be available and the mitigation algorithms produce at least .Cm minclock survivors in order to synchronize the clock. Byzantine agreement principles require at least four candidates in order to correctly discard a single falseticker. For legacy purposes, .Cm minsane defaults to 1 and .Cm minclock defaults to 3. For manycast service .Cm minsane should be explicitly set to 4, assuming at least that number of servers are available. .Pp If at least .Cm minclock servers are found, the manycast poll interval is immediately set to eight times .Cm maxpoll . If less than .Cm minclock servers are found when the TTL has reached the maximum hops, the manycast poll interval is doubled. For each transmission after that, the poll interval is doubled again until reaching the maximum of eight times .Cm maxpoll . Further transmissions use the same poll interval and TTL values. Note that while all this is going on, each client/server association found is operating normally it the system poll interval. .Pp Administratively scoped multicast boundaries are normally specified by the network router configuration and, in the case of IPv6, the link/site scope prefix. By default, the increment for TTL hops is 32 starting from 31; however, the .Ic ttl configuration command can be used to modify the values to match the scope rules. .Pp It is often useful to narrow the range of acceptable servers which can be found by manycast client associations. Because manycast servers respond only when the client stratum is equal to or greater than the server stratum, primary (stratum 1) servers fill find only primary servers in TTL range, which is probably the most common objective. However, unless configured otherwise, all manycast clients in TTL range will eventually find all primary servers in TTL range, which is probably not the most common objective in large networks. The .Ic tos command can be used to modify this behavior. Servers with stratum below .Cm floor or above .Cm ceiling specified in the .Ic tos command are strongly discouraged during the selection process; however, these servers may be temporally accepted if the number of servers within TTL range is less than .Cm minclock . .Pp The above actions occur for each manycast client message, which repeats at the designated poll interval. However, once the ephemeral client association is mobilized, subsequent manycast server replies are discarded, since that would result in a duplicate association. If during a poll interval the number of client associations falls below .Cm minclock , all manycast client prototype associations are reset to the initial poll interval and TTL hops and operation resumes from the beginning. It is important to avoid frequent manycast client messages, since each one requires all manycast servers in TTL range to respond. The result could well be an implosion, either minor or major, depending on the number of servers in range. The recommended value for .Cm maxpoll is 12 (4,096 s). .Pp It is possible and frequently useful to configure a host as both manycast client and manycast server. A number of hosts configured this way and sharing a common group address will automatically organize themselves in an optimum configuration based on stratum and synchronization distance. For example, consider an NTP subnet of two primary servers and a hundred or more dependent clients. With two exceptions, all servers and clients have identical configuration files including both .Ic multicastclient and .Ic multicastserver commands using, for instance, multicast group address 239.1.1.1. The only exception is that each primary server configuration file must include commands for the primary reference source such as a GPS receiver. .Pp The remaining configuration files for all secondary servers and clients have the same contents, except for the .Ic tos command, which is specific for each stratum level. For stratum 1 and stratum 2 servers, that command is not necessary. For stratum 3 and above servers the .Cm floor value is set to the intended stratum number. Thus, all stratum 3 configuration files are identical, all stratum 4 files are identical and so forth. .Pp Once operations have stabilized in this scenario, the primary servers will find the primary reference source and each other, since they both operate at the same stratum (1), but not with any secondary server or client, since these operate at a higher stratum. The secondary servers will find the servers at the same stratum level. If one of the primary servers loses its GPS receiver, it will continue to operate as a client and other clients will time out the corresponding association and re\-associate accordingly. .Pp Some administrators prefer to avoid running .Xr ntpd 8 continuously and run either .Xr sntp 8 or .Xr ntpd 8 .Fl q as a cron job. In either case the servers must be configured in advance and the program fails if none are available when the cron job runs. A really slick application of manycast is with .Xr ntpd 8 .Fl q . The program wakes up, scans the local landscape looking for the usual suspects, selects the best from among the rascals, sets the clock and then departs. Servers do not have to be configured in advance and all clients throughout the network can have the same configuration file. .Ss Manycast Interactions with Autokey Each time a manycast client sends a client mode packet to a multicast group address, all manycast servers in scope generate a reply including the host name and status word. The manycast clients then run the Autokey protocol, which collects and verifies all certificates involved. Following the burst interval all but three survivors are cast off, but the certificates remain in the local cache. It often happens that several complete signing trails from the client to the primary servers are collected in this way. .Pp About once an hour or less often if the poll interval exceeds this, the client regenerates the Autokey key list. This is in general transparent in client/server mode. However, about once per day the server private value used to generate cookies is refreshed along with all manycast client associations. In this case all cryptographic values including certificates is refreshed. If a new certificate has been generated since the last refresh epoch, it will automatically revoke all prior certificates that happen to be in the certificate cache. At the same time, the manycast scheme starts all over from the beginning and the expanding ring shrinks to the minimum and increments from there while collecting all servers in scope. .Ss Broadcast Options .Bl -tag -width indent .It Xo Ic tos .Oo .Cm bcpollbstep Ar gate .Oc .Xc This command provides a way to delay, by the specified number of broadcast poll intervals, believing backward time steps from a broadcast server. Broadcast time networks are expected to be trusted. In the event a broadcast server's time is stepped backwards, there is clear benefit to having the clients notice this change as soon as possible. Attacks such as replay attacks can happen, however, and even though there are a number of protections built in to broadcast mode, attempts to perform a replay attack are possible. This value defaults to 0, but can be changed to any number of poll intervals between 0 and 4. .El .Ss Manycast Options .Bl -tag -width indent .It Xo Ic tos .Oo .Cm ceiling Ar ceiling | .Cm cohort { 0 | 1 } | .Cm floor Ar floor | .Cm minclock Ar minclock | .Cm minsane Ar minsane .Oc .Xc This command affects the clock selection and clustering algorithms. It can be used to select the quality and quantity of peers used to synchronize the system clock and is most useful in manycast mode. The variables operate as follows: .Bl -tag -width indent .It Cm ceiling Ar ceiling Peers with strata above .Cm ceiling will be discarded if there are at least .Cm minclock peers remaining. This value defaults to 15, but can be changed to any number from 1 to 15. .It Cm cohort Bro 0 | 1 Brc This is a binary flag which enables (0) or disables (1) manycast server replies to manycast clients with the same stratum level. This is useful to reduce implosions where large numbers of clients with the same stratum level are present. The default is to enable these replies. .It Cm floor Ar floor Peers with strata below .Cm floor will be discarded if there are at least .Cm minclock peers remaining. This value defaults to 1, but can be changed to any number from 1 to 15. .It Cm minclock Ar minclock The clustering algorithm repeatedly casts out outlier associations until no more than .Cm minclock associations remain. This value defaults to 3, but can be changed to any number from 1 to the number of configured sources. .It Cm minsane Ar minsane This is the minimum number of candidates available to the clock selection algorithm in order to produce one or more truechimers for the clustering algorithm. If fewer than this number are available, the clock is undisciplined and allowed to run free. The default is 1 for legacy purposes. However, according to principles of Byzantine agreement, .Cm minsane should be at least 4 in order to detect and discard a single falseticker. .El .It Cm ttl Ar hop ... This command specifies a list of TTL values in increasing order, up to 8 values can be specified. In manycast mode these values are used in turn in an expanding\-ring search. The default is eight multiples of 32 starting at 31. .El .Sh Reference Clock Support The NTP Version 4 daemon supports some three dozen different radio, satellite and modem reference clocks plus a special pseudo\-clock used for backup or when no other clock source is available. Detailed descriptions of individual device drivers and options can be found in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . Additional information can be found in the pages linked there, including the .Qq Debugging Hints for Reference Clock Drivers and .Qq How To Write a Reference Clock Driver pages (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . In addition, support for a PPS signal is available as described in the .Qq Pulse\-per\-second (PPS) Signal Interfacing page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . Many drivers support special line discipline/streams modules which can significantly improve the accuracy using the driver. These are described in the .Qq Line Disciplines and Streams Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Pp A reference clock will generally (though not always) be a radio timecode receiver which is synchronized to a source of standard time such as the services offered by the NRC in Canada and NIST and USNO in the US. The interface between the computer and the timecode receiver is device dependent, but is usually a serial port. A device driver specific to each reference clock must be selected and compiled in the distribution; however, most common radio, satellite and modem clocks are included by default. Note that an attempt to configure a reference clock when the driver has not been compiled or the hardware port has not been appropriately configured results in a scalding remark to the system log file, but is otherwise non hazardous. .Pp For the purposes of configuration, .Xr ntpd 8 treats reference clocks in a manner analogous to normal NTP peers as much as possible. Reference clocks are identified by a syntactically correct but invalid IP address, in order to distinguish them from normal NTP peers. Reference clock addresses are of the form .Sm off .Li 127.127. Ar t . Ar u , .Sm on where .Ar t is an integer denoting the clock type and .Ar u indicates the unit number in the range 0\-3. While it may seem overkill, it is in fact sometimes useful to configure multiple reference clocks of the same type, in which case the unit numbers must be unique. .Pp The .Ic server command is used to configure a reference clock, where the .Ar address argument in that command is the clock address. The .Cm key , .Cm version and .Cm ttl options are not used for reference clock support. The .Cm mode option is added for reference clock support, as described below. The .Cm prefer option can be useful to persuade the server to cherish a reference clock with somewhat more enthusiasm than other reference clocks or peers. Further information on this option can be found in the .Qq Mitigation Rules and the prefer Keyword (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) page. The .Cm minpoll and .Cm maxpoll options have meaning only for selected clock drivers. See the individual clock driver document pages for additional information. .Pp The .Ic fudge command is used to provide additional information for individual clock drivers and normally follows immediately after the .Ic server command. The .Ar address argument specifies the clock address. The .Cm refid and .Cm stratum options can be used to override the defaults for the device. There are two optional device\-dependent time offsets and four flags that can be included in the .Ic fudge command as well. .Pp The stratum number of a reference clock is by default zero. Since the .Xr ntpd 8 daemon adds one to the stratum of each peer, a primary server ordinarily displays an external stratum of one. In order to provide engineered backups, it is often useful to specify the reference clock stratum as greater than zero. The .Cm stratum option is used for this purpose. Also, in cases involving both a reference clock and a pulse\-per\-second (PPS) discipline signal, it is useful to specify the reference clock identifier as other than the default, depending on the driver. The .Cm refid option is used for this purpose. Except where noted, these options apply to all clock drivers. .Ss Reference Clock Commands .Bl -tag -width indent .It Xo Ic server .Sm off .Li 127.127. Ar t . Ar u .Sm on .Op Cm prefer .Op Cm mode Ar int .Op Cm minpoll Ar int .Op Cm maxpoll Ar int .Xc This command can be used to configure reference clocks in special ways. The options are interpreted as follows: .Bl -tag -width indent .It Cm prefer Marks the reference clock as preferred. All other things being equal, this host will be chosen for synchronization among a set of correctly operating hosts. See the .Qq Mitigation Rules and the prefer Keyword page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) for further information. .It Cm mode Ar int Specifies a mode number which is interpreted in a device\-specific fashion. For instance, it selects a dialing protocol in the ACTS driver and a device subtype in the parse drivers. .It Cm minpoll Ar int .It Cm maxpoll Ar int These options specify the minimum and maximum polling interval for reference clock messages, as a power of 2 in seconds For most directly connected reference clocks, both .Cm minpoll and .Cm maxpoll default to 6 (64 s). For modem reference clocks, .Cm minpoll defaults to 10 (17.1 m) and .Cm maxpoll defaults to 14 (4.5 h). The allowable range is 4 (16 s) to 17 (36.4 h) inclusive. .El .It Xo Ic fudge .Sm off .Li 127.127. Ar t . Ar u .Sm on .Op Cm time1 Ar sec .Op Cm time2 Ar sec .Op Cm stratum Ar int .Op Cm refid Ar string .Op Cm mode Ar int .Op Cm flag1 Cm 0 \&| Cm 1 .Op Cm flag2 Cm 0 \&| Cm 1 .Op Cm flag3 Cm 0 \&| Cm 1 .Op Cm flag4 Cm 0 \&| Cm 1 .Xc This command can be used to configure reference clocks in special ways. It must immediately follow the .Ic server command which configures the driver. Note that the same capability is possible at run time using the .Xr ntpdc 8 program. The options are interpreted as follows: .Bl -tag -width indent .It Cm time1 Ar sec Specifies a constant to be added to the time offset produced by the driver, a fixed\-point decimal number in seconds. This is used as a calibration constant to adjust the nominal time offset of a particular clock to agree with an external standard, such as a precision PPS signal. It also provides a way to correct a systematic error or bias due to serial port or operating system latencies, different cable lengths or receiver internal delay. The specified offset is in addition to the propagation delay provided by other means, such as internal DIPswitches. Where a calibration for an individual system and driver is available, an approximate correction is noted in the driver documentation pages. Note: in order to facilitate calibration when more than one radio clock or PPS signal is supported, a special calibration feature is available. It takes the form of an argument to the .Ic enable command described in .Sx Miscellaneous Options page and operates as described in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .It Cm time2 Ar secs Specifies a fixed\-point decimal number in seconds, which is interpreted in a driver\-dependent way. See the descriptions of specific drivers in the .Qq Reference Clock Drivers page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ). .It Cm stratum Ar int Specifies the stratum number assigned to the driver, an integer between 0 and 15. This number overrides the default stratum number ordinarily assigned by the driver itself, usually zero. .It Cm refid Ar string Specifies an ASCII string of from one to four characters which defines the reference identifier used by the driver. This string overrides the default identifier ordinarily assigned by the driver itself. .It Cm mode Ar int Specifies a mode number which is interpreted in a device\-specific fashion. For instance, it selects a dialing protocol in the ACTS driver and a device subtype in the parse drivers. .It Cm flag1 Cm 0 \&| Cm 1 .It Cm flag2 Cm 0 \&| Cm 1 .It Cm flag3 Cm 0 \&| Cm 1 .It Cm flag4 Cm 0 \&| Cm 1 These four flags are used for customizing the clock driver. The interpretation of these values, and whether they are used at all, is a function of the particular clock driver. However, by convention .Cm flag4 is used to enable recording monitoring data to the .Cm clockstats file configured with the .Ic filegen command. Further information on the .Ic filegen command can be found in .Sx Monitoring Options . .El .El .Sh Miscellaneous Options .Bl -tag -width indent .It Ic broadcastdelay Ar seconds The broadcast and multicast modes require a special calibration to determine the network delay between the local and remote servers. Ordinarily, this is done automatically by the initial protocol exchanges between the client and server. In some cases, the calibration procedure may fail due to network or server access controls, for example. This command specifies the default delay to be used under these circumstances. Typically (for Ethernet), a number between 0.003 and 0.007 seconds is appropriate. The default when this command is not used is 0.004 seconds. .It Ic calldelay Ar delay This option controls the delay in seconds between the first and second packets sent in burst or iburst mode to allow additional time for a modem or ISDN call to complete. .It Ic driftfile Ar driftfile This command specifies the complete path and name of the file used to record the frequency of the local clock oscillator. This is the same operation as the .Fl f command line option. If the file exists, it is read at startup in order to set the initial frequency and then updated once per hour with the current frequency computed by the daemon. If the file name is specified, but the file itself does not exist, the starts with an initial frequency of zero and creates the file when writing it for the first time. If this command is not given, the daemon will always start with an initial frequency of zero. .Pp The file format consists of a single line containing a single floating point number, which records the frequency offset measured in parts\-per\-million (PPM). The file is updated by first writing the current drift value into a temporary file and then renaming this file to replace the old version. This implies that .Xr ntpd 8 must have write permission for the directory the drift file is located in, and that file system links, symbolic or otherwise, should be avoided. .It Ic dscp Ar value This option specifies the Differentiated Services Control Point (DSCP) value, a 6\-bit code. The default value is 46, signifying Expedited Forwarding. .It Xo Ic enable .Oo .Cm auth | Cm bclient | .Cm calibrate | Cm kernel | .Cm mode7 | Cm monitor | .Cm ntp | Cm stats | .Cm peer_clear_digest_early | .Cm unpeer_crypto_early | Cm unpeer_crypto_nak_early | Cm unpeer_digest_early .Oc .Xc .It Xo Ic disable .Oo .Cm auth | Cm bclient | .Cm calibrate | Cm kernel | .Cm mode7 | Cm monitor | .Cm ntp | Cm stats | .Cm peer_clear_digest_early | .Cm unpeer_crypto_early | Cm unpeer_crypto_nak_early | Cm unpeer_digest_early .Oc .Xc Provides a way to enable or disable various server options. Flags not mentioned are unaffected. Note that all of these flags can be controlled remotely using the .Xr ntpdc 8 utility program. .Bl -tag -width indent .It Cm auth Enables the server to synchronize with unconfigured peers only if the peer has been correctly authenticated using either public key or private key cryptography. The default for this flag is .Ic enable . .It Cm bclient Enables the server to listen for a message from a broadcast or multicast server, as in the .Ic multicastclient command with default address. The default for this flag is .Ic disable . .It Cm calibrate Enables the calibrate feature for reference clocks. The default for this flag is .Ic disable . .It Cm kernel Enables the kernel time discipline, if available. The default for this flag is .Ic enable if support is available, otherwise .Ic disable . .It Cm mode7 Enables processing of NTP mode 7 implementation\-specific requests which are used by the deprecated .Xr ntpdc 8 program. The default for this flag is disable. This flag is excluded from runtime configuration using .Xr ntpq 8 . The .Xr ntpq 8 program provides the same capabilities as .Xr ntpdc 8 using standard mode 6 requests. .It Cm monitor Enables the monitoring facility. See the .Xr ntpdc 8 program and the .Ic monlist command or further information. The default for this flag is .Ic enable . .It Cm ntp Enables time and frequency discipline. In effect, this switch opens and closes the feedback loop, which is useful for testing. The default for this flag is .Ic enable . .It Cm peer_clear_digest_early By default, if .Xr ntpd 8 is using autokey and it receives a crypto\-NAK packet that passes the duplicate packet and origin timestamp checks the peer variables are immediately cleared. While this is generally a feature as it allows for quick recovery if a server key has changed, a properly forged and appropriately delivered crypto\-NAK packet can be used in a DoS attack. If you have active noticeable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm stats Enables the statistics facility. See the .Sx Monitoring Options section for further information. The default for this flag is .Ic disable . .It Cm unpeer_crypto_early By default, if .Xr ntpd 8 receives an autokey packet that fails TEST9, a crypto failure, the association is immediately cleared. This is almost certainly a feature, but if, in spite of the current recommendation of not using autokey, you are .B still using autokey .B and you are seeing this sort of DoS attack disabling this flag will delay tearing down the association until the reachability counter becomes zero. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm unpeer_crypto_nak_early By default, if .Xr ntpd 8 receives a crypto\-NAK packet that passes the duplicate packet and origin timestamp checks the association is immediately cleared. While this is generally a feature as it allows for quick recovery if a server key has changed, a properly forged and appropriately delivered crypto\-NAK packet can be used in a DoS attack. If you have active noticeable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .It Cm unpeer_digest_early By default, if .Xr ntpd 8 receives what should be an authenticated packet that passes other packet sanity checks but contains an invalid digest the association is immediately cleared. While this is generally a feature as it allows for quick recovery, if this type of packet is carefully forged and sent during an appropriate window it can be used for a DoS attack. If you have active noticeable problems with this type of DoS attack then you should consider disabling this option. You can check your .Cm peerstats file for evidence of any of these attacks. The default for this flag is .Ic enable . .El .It Ic includefile Ar includefile This command allows additional configuration commands to be included from a separate file. Include files may be nested to a depth of five; upon reaching the end of any include file, command processing resumes in the previous configuration file. This option is useful for sites that run .Xr ntpd 8 on multiple hosts, with (mostly) common options (e.g., a restriction list). .It Xo Ic interface .Oo .Cm listen | Cm ignore | Cm drop .Oc .Oo .Cm all | Cm ipv4 | Cm ipv6 | Cm wildcard .Ar name | Ar address .Oo Cm / Ar prefixlen .Oc .Oc .Xc The .Cm interface directive controls which network addresses .Xr ntpd 8 opens, and whether input is dropped without processing. The first parameter determines the action for addresses which match the second parameter. The second parameter specifies a class of addresses, or a specific interface name, or an address. In the address case, .Ar prefixlen determines how many bits must match for this rule to apply. .Cm ignore prevents opening matching addresses, .Cm drop causes .Xr ntpd 8 to open the address and drop all received packets without examination. Multiple .Cm interface directives can be used. The last rule which matches a particular address determines the action for it. .Cm interface directives are disabled if any .Fl I , .Fl \-interface , .Fl L , or .Fl \-novirtualips command\-line options are specified in the configuration file, all available network addresses are opened. The .Cm nic directive is an alias for .Cm interface . .It Ic leapfile Ar leapfile This command loads the IERS leapseconds file and initializes the leapsecond values for the next leapsecond event, leapfile expiration time, and TAI offset. The file can be obtained directly from the IERS at .Li https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap\-seconds.list or .Li ftp://hpiers.obspm.fr/iers/bul/bulc/ntp/leap\-seconds.list . The .Cm leapfile is scanned when .Xr ntpd 8 processes the .Cm leapfile directive or when .Cm ntpd detects that the .Ar leapfile has changed. .Cm ntpd checks once a day to see if the .Ar leapfile has changed. The .Xr update\-leap 1update_leapmdoc script can be run to see if the .Ar leapfile should be updated. .It Ic leapsmearinterval Ar seconds This EXPERIMENTAL option is only available if .Xr ntpd 8 was built with the .Cm \-\-enable\-leap\-smear option to the .Cm configure script. It specifies the interval over which a leap second correction will be applied. Recommended values for this option are between 7200 (2 hours) and 86400 (24 hours). .Sy DO NOT USE THIS OPTION ON PUBLIC\-ACCESS SERVERS! See http://bugs.ntp.org/2855 for more information. .It Ic logconfig Ar configkeyword This command controls the amount and type of output written to the system .Xr syslog 3 facility or the alternate .Ic logfile log file. By default, all output is turned on. All .Ar configkeyword keywords can be prefixed with .Ql = , .Ql + and .Ql \- , where .Ql = sets the .Xr syslog 3 priority mask, .Ql + adds and .Ql \- removes messages. .Xr syslog 3 messages can be controlled in four classes .Po .Cm clock , .Cm peer , .Cm sys and .Cm sync .Pc . Within these classes four types of messages can be controlled: informational messages .Po .Cm info .Pc , event messages .Po .Cm events .Pc , statistics messages .Po .Cm statistics .Pc and status messages .Po .Cm status .Pc . .Pp Configuration keywords are formed by concatenating the message class with the event class. The .Cm all prefix can be used instead of a message class. A message class may also be followed by the .Cm all keyword to enable/disable all messages of the respective message class. Thus, a minimal log configuration could look like this: .Bd -literal logconfig =syncstatus +sysevents .Ed .Pp This would just list the synchronizations state of .Xr ntpd 8 and the major system events. For a simple reference server, the following minimum message configuration could be useful: .Bd -literal logconfig =syncall +clockall .Ed .Pp This configuration will list all clock information and synchronization information. All other events and messages about peers, system events and so on is suppressed. .It Ic logfile Ar logfile This command specifies the location of an alternate log file to be used instead of the default system .Xr syslog 3 facility. This is the same operation as the .Fl l command line option. .It Xo Ic mru .Oo .Cm maxdepth Ar count | Cm maxmem Ar kilobytes | .Cm mindepth Ar count | Cm maxage Ar seconds | .Cm initialloc Ar count | Cm initmem Ar kilobytes | .Cm incalloc Ar count | Cm incmem Ar kilobytes .Oc .Xc Controls size limit of the monitoring facility's Most Recently Used (MRU) list of client addresses, which is also used by the rate control facility. .Bl -tag -width indent .It Ic maxdepth Ar count .It Ic maxmem Ar kilobytes Equivalent upper limits on the size of the MRU list, in terms of entries or kilobytes. The actual limit will be up to .Cm incalloc entries or .Cm incmem kilobytes larger. As with all of the .Cm mru options offered in units of entries or kilobytes, if both .Cm maxdepth and .Cm maxmem are used, the last one used controls. The default is 1024 kilobytes. .It Cm mindepth Ar count Lower limit on the MRU list size. When the MRU list has fewer than .Cm mindepth entries, existing entries are never removed to make room for newer ones, regardless of their age. The default is 600 entries. .It Cm maxage Ar seconds Once the MRU list has .Cm mindepth entries and an additional client is to be added to the list, if the oldest entry was updated more than .Cm maxage seconds ago, that entry is removed and its storage is reused. If the oldest entry was updated more recently the MRU list is grown, subject to .Cm maxdepth / moxmem . The default is 64 seconds. .It Cm initalloc Ar count .It Cm initmem Ar kilobytes Initial memory allocation at the time the monitoringfacility is first enabled, in terms of the number of entries or kilobytes. The default is 4 kilobytes. .It Cm incalloc Ar count .It Cm incmem Ar kilobytes Size of additional memory allocations when growing the MRU list, in entries or kilobytes. The default is 4 kilobytes. .El .It Ic nonvolatile Ar threshold Specify the .Ar threshold delta in seconds before an hourly change to the .Cm driftfile (frequency file) will be written, with a default value of 1e\-7 (0.1 PPM). The frequency file is inspected each hour. If the difference between the current frequency and the last value written exceeds the threshold, the file is written and the .Cm threshold becomes the new threshold value. If the threshold is not exceeeded, it is reduced by half. This is intended to reduce the number of file writes for embedded systems with nonvolatile memory. .It Ic phone Ar dial ... This command is used in conjunction with the ACTS modem driver (type 18) or the JJY driver (type 40, mode 100 \- 180). For the ACTS modem driver (type 18), the arguments consist of a maximum of 10 telephone numbers used to dial USNO, NIST, or European time service. For the JJY driver (type 40 mode 100 \- 180), the argument is one telephone number used to dial the telephone JJY service. The Hayes command ATDT is normally prepended to the number. The number can contain other modem control codes as well. .It Xo Ic reset .Oo .Ic allpeers .Oc .Oo .Ic auth .Oc .Oo .Ic ctl .Oc .Oo .Ic io .Oc .Oo .Ic mem .Oc .Oo .Ic sys .Oc .Oo .Ic timer .Oc .Xc Reset one or more groups of counters maintained by .Cm ntpd and exposed by .Cm ntpq and .Cm ntpdc . .It Xo Ic rlimit .Oo .Cm memlock Ar Nmegabytes | .Cm stacksize Ar N4kPages .Cm filenum Ar Nfiledescriptors .Oc .Xc .Bl -tag -width indent .It Cm memlock Ar Nmegabytes Specify the number of megabytes of memory that should be allocated and locked. Probably only available under Linux, this option may be useful when dropping root (the .Fl i option). The default is \-1. -1 means "do not lock the process into memory". 0 means "lock whatever memory the process wants into memory". .It Cm stacksize Ar N4kPages Specifies the maximum size of the process stack on systems with the .Fn mlockall function. Defaults to 50 4k pages (200 4k pages in OpenBSD). .It Cm filenum Ar Nfiledescriptors Specifies the maximum number of file descriptors ntpd may have open at once. Defaults to the system default. .El .It Ic saveconfigdir Ar directory_path Specify the directory in which to write configuration snapshots requested with .Cm ntpq 's .Cm saveconfig command. If .Cm saveconfigdir does not appear in the configuration file, .Cm saveconfig requests are rejected by .Cm ntpd . .It Ic saveconfig Ar filename Write the current configuration, including any runtime modifications given with .Cm :config or .Cm config\-from\-file to the .Cm ntpd host's .Ar filename in the .Cm saveconfigdir . This command will be rejected unless the .Cm saveconfigdir directive appears in .Cm ntpd 's configuration file. .Ar filename can use .Xr strftime 3 format directives to substitute the current date and time, for example, .Cm saveconfig\ ntp\-%Y%m%d\-%H%M%S.conf . The filename used is stored in the system variable .Cm savedconfig . Authentication is required. .It Ic setvar Ar variable Op Cm default This command adds an additional system variable. These variables can be used to distribute additional information such as the access policy. If the variable of the form .Sm off .Va name = Ar value .Sm on is followed by the .Cm default keyword, the variable will be listed as part of the default system variables .Po .Xr ntpq 8 .Ic rv command .Pc ) . These additional variables serve informational purposes only. They are not related to the protocol other that they can be listed. The known protocol variables will always override any variables defined via the .Ic setvar mechanism. There are three special variables that contain the names of all variable of the same group. The .Va sys_var_list holds the names of all system variables. The .Va peer_var_list holds the names of all peer variables and the .Va clock_var_list holds the names of the reference clock variables. .It Cm sysinfo Display operational summary. .It Cm sysstats Show statistics counters maintained in the protocol module. .It Xo Ic tinker .Oo .Cm allan Ar allan | .Cm dispersion Ar dispersion | .Cm freq Ar freq | .Cm huffpuff Ar huffpuff | .Cm panic Ar panic | .Cm step Ar step | .Cm stepback Ar stepback | .Cm stepfwd Ar stepfwd | .Cm stepout Ar stepout .Oc .Xc This command can be used to alter several system variables in very exceptional circumstances. It should occur in the configuration file before any other configuration options. The default values of these variables have been carefully optimized for a wide range of network speeds and reliability expectations. In general, they interact in intricate ways that are hard to predict and some combinations can result in some very nasty behavior. Very rarely is it necessary to change the default values; but, some folks cannot resist twisting the knobs anyway and this command is for them. Emphasis added: twisters are on their own and can expect no help from the support group. .Pp The variables operate as follows: .Bl -tag -width indent .It Cm allan Ar allan The argument becomes the new value for the minimum Allan intercept, which is a parameter of the PLL/FLL clock discipline algorithm. The value in log2 seconds defaults to 7 (1024 s), which is also the lower limit. .It Cm dispersion Ar dispersion The argument becomes the new value for the dispersion increase rate, normally .000015 s/s. .It Cm freq Ar freq The argument becomes the initial value of the frequency offset in parts\-per\-million. This overrides the value in the frequency file, if present, and avoids the initial training state if it is not. .It Cm huffpuff Ar huffpuff The argument becomes the new value for the experimental huff\-n'\-puff filter span, which determines the most recent interval the algorithm will search for a minimum delay. The lower limit is 900 s (15 m), but a more reasonable value is 7200 (2 hours). There is no default, since the filter is not enabled unless this command is given. .It Cm panic Ar panic The argument is the panic threshold, normally 1000 s. If set to zero, the panic sanity check is disabled and a clock offset of any value will be accepted. .It Cm step Ar step The argument is the step threshold, which by default is 0.128 s. It can be set to any positive number in seconds. If set to zero, step adjustments will never occur. Note: The kernel time discipline is disabled if the step threshold is set to zero or greater than the default. .It Cm stepback Ar stepback The argument is the step threshold for the backward direction, which by default is 0.128 s. It can be set to any positive number in seconds. If both the forward and backward step thresholds are set to zero, step adjustments will never occur. Note: The kernel time discipline is disabled if each direction of step threshold are either set to zero or greater than .5 second. .It Cm stepfwd Ar stepfwd As for stepback, but for the forward direction. .It Cm stepout Ar stepout The argument is the stepout timeout, which by default is 900 s. It can be set to any positive number in seconds. If set to zero, the stepout pulses will not be suppressed. .El .It Cm writevar Ar assocID\ name = value [,...] Write (create or update) the specified variables. If the .Cm assocID is zero, the variablea re from the system variables name space, otherwise they are from the peer variables name space. The .Cm assocID is required, as the same name can occur in both name spaces. .It Xo Ic trap Ar host_address .Op Cm port Ar port_number .Op Cm interface Ar interface_address .Xc This command configures a trap receiver at the given host address and port number for sending messages with the specified local interface address. If the port number is unspecified, a value of 18447 is used. If the interface address is not specified, the message is sent with a source address of the local interface the message is sent through. Note that on a multihomed host the interface used may vary from time to time with routing changes. .It Cm ttl Ar hop ... This command specifies a list of TTL values in increasing order. Up to 8 values can be specified. In .Cm manycast mode these values are used in\-turn in an expanding\-ring search. The default is eight multiples of 32 starting at 31. .Pp The trap receiver will generally log event messages and other information from the server in a log file. While such monitor programs may also request their own trap dynamically, configuring a trap receiver will ensure that no messages are lost when the server is started. .It Cm hop Ar ... This command specifies a list of TTL values in increasing order, up to 8 values can be specified. In manycast mode these values are used in turn in an expanding\-ring search. The default is eight multiples of 32 starting at 31. .El .Sh "OPTIONS" .Bl -tag .It Fl \-help Display usage information and exit. .It Fl \-more\-help Pass the extended usage information through a pager. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from environment variables named: .nf \fBNTP_CONF_\fP or \fBNTP_CONF\fP .fi .ad .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh FILES .Bl -tag -width /etc/ntp.drift -compact .It Pa /etc/ntp.conf the default name of the configuration file .It Pa ntp.keys private MD5 keys .It Pa ntpkey RSA private key .It Pa ntpkey_ Ns Ar host RSA public key .It Pa ntp_dh Diffie\-Hellman agreement parameters .El .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh "SEE ALSO" .Xr ntpd 8 , .Xr ntpdc 8 , .Xr ntpq 8 .Pp In addition to the manual pages provided, comprehensive documentation is available on the world wide web at .Li http://www.ntp.org/ . A snapshot of this documentation is available in HTML format in .Pa /usr/share/doc/ntp . .Rs .%A David L. Mills .%T Network Time Protocol (Version 4) .%O RFC5905 .Re .Sh "AUTHORS" The University of Delaware and Network Time Foundation .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh BUGS The syntax checking is not picky; some combinations of ridiculous and even hilarious options and modes may not be detected. .Pp The .Pa ntpkey_ Ns Ar host files are really digital certificates. These should be obtained via secure directory services when they become universally available. .Pp Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh NOTES This document was derived from FreeBSD. .Pp This manual page was \fIAutoGen\fP\-erated from the \fBntp.conf\fP option definitions. diff --git a/usr.sbin/ntp/doc/ntp.keys.5 b/usr.sbin/ntp/doc/ntp.keys.5 index d235f3b5f7dd..6bec2880163e 100644 --- a/usr.sbin/ntp/doc/ntp.keys.5 +++ b/usr.sbin/ntp/doc/ntp.keys.5 @@ -1,174 +1,174 @@ .Dd August 14 2018 .Dt NTP_KEYS 5 File Formats .Os SunOS 5.10 .\" EDIT THIS FILE WITH CAUTION (ntp.mdoc) .\" .\" It has been AutoGen-ed August 14, 2018 at 08:29:18 AM by AutoGen 5.18.5 .\" From the definitions ntp.keys.def .\" and the template file agmdoc-file.tpl .Sh NAME .Nm ntp.keys .Nd NTP symmetric key file format .Sh NAME .Nm ntp.keys -.Nd NTP symmetric key file format +.Nd Network Time Protocol symmetric key format .Sh SYNOPSIS .Nm .Op Fl \-option\-name .Op Fl \-option\-name Ar value .Pp All arguments must be options. .Pp .Sh DESCRIPTION This document describes the format of an NTP symmetric key file. For a description of the use of this type of file, see the .Qq Authentication Support section of the .Xr ntp.conf 5 page. .Pp .Xr ntpd 8 reads its keys from a file specified using the .Fl k command line option or the .Ic keys statement in the configuration file. While key number 0 is fixed by the NTP standard (as 56 zero bits) and may not be changed, one or more keys numbered between 1 and 65535 may be arbitrarily set in the keys file. .Pp The key file uses the same comment conventions as the configuration file. Key entries use a fixed format of the form .Pp .D1 Ar keyno type key opt_IP_list .Pp where .Ar keyno is a positive integer (between 1 and 65535), .Ar type is the message digest algorithm, .Ar key is the key itself, and .Ar opt_IP_list is an optional comma\-separated list of IPs where the .Ar keyno should be trusted. that are allowed to serve time. Each IP in .Ar opt_IP_list may contain an optional .Cm /subnetbits specification which identifies the number of bits for the desired subnet of trust. If .Ar opt_IP_list is empty, any properly\-authenticated message will be accepted. .Pp The .Ar key may be given in a format controlled by the .Ar type field. The .Ar type .Li MD5 is always supported. If .Li ntpd was built with the OpenSSL library then any digest library supported by that library may be specified. However, if compliance with FIPS 140\-2 is required the .Ar type must be either .Li SHA or .Li SHA1 . .Pp What follows are some key types, and corresponding formats: .Pp .Bl -tag -width RMD160 -compact .It Li MD5 The key is 1 to 16 printable characters terminated by an EOL, whitespace, or a .Li # (which is the "start of comment" character). .Pp .It Li SHA .It Li SHA1 .It Li RMD160 The key is a hex\-encoded ASCII string of 40 characters, which is truncated as necessary. .El .Pp Note that the keys used by the .Xr ntpq 8 and .Xr ntpdc 8 programs are checked against passwords requested by the programs and entered by hand, so it is generally appropriate to specify these keys in ASCII format. .Sh "OPTIONS" .Bl -tag .It Fl \-help Display usage information and exit. .It Fl \-more\-help Pass the extended usage information through a pager. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from environment variables named: .nf \fBNTP_KEYS_\fP or \fBNTP_KEYS\fP .fi .ad .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh FILES .Bl -tag -width /etc/ntp.keys -compact .It Pa /etc/ntp.keys the default name of the configuration file .El .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh "SEE ALSO" .Xr ntp.conf 5 , .Xr ntpd 8 , .Xr ntpdate 8 , .Xr ntpdc 8 , .Xr sntp 8 .Sh "AUTHORS" The University of Delaware and Network Time Foundation .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh "BUGS" Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh NOTES This document was derived from FreeBSD. .Pp This manual page was \fIAutoGen\fP\-erated from the \fBntp.keys\fP option definitions. diff --git a/usr.sbin/ntp/doc/ntpd.8 b/usr.sbin/ntp/doc/ntpd.8 index 74bc07793048..83beac3632a9 100644 --- a/usr.sbin/ntp/doc/ntpd.8 +++ b/usr.sbin/ntp/doc/ntpd.8 @@ -1,908 +1,908 @@ .Dd August 14 2018 .Dt NTPD 8 User Commands .Os .\" EDIT THIS FILE WITH CAUTION (ntpd-opts.mdoc) .\" .\" It has been AutoGen-ed August 14, 2018 at 08:29:20 AM by AutoGen 5.18.5 .\" From the definitions ntpd-opts.def .\" and the template file agmdoc-cmd.tpl .Sh NAME .Nm ntpd -.Nd NTP daemon program +.Nd set clock via Network Time Protocol daemon .Sh SYNOPSIS .Nm .\" Mixture of short (flag) options and long options .Op Fl flags .Op Fl flag Op Ar value .Op Fl \-option\-name Ns Oo Oo Ns "=| " Oc Ns Ar value Oc [ ... ] .Pp .Sh DESCRIPTION The .Nm utility is an operating system daemon which sets and maintains the system time of day in synchronism with Internet standard time servers. It is a complete implementation of the Network Time Protocol (NTP) version 4, as defined by RFC\-5905, but also retains compatibility with version 3, as defined by RFC\-1305, and versions 1 and 2, as defined by RFC\-1059 and RFC\-1119, respectively. .Pp The .Nm utility does most computations in 64\-bit floating point arithmetic and does relatively clumsy 64\-bit fixed point operations only when necessary to preserve the ultimate precision, about 232 picoseconds. While the ultimate precision is not achievable with ordinary workstations and networks of today, it may be required with future gigahertz CPU clocks and gigabit LANs. .Pp Ordinarily, .Nm reads the .Xr ntp.conf 5 configuration file at startup time in order to determine the synchronization sources and operating modes. It is also possible to specify a working, although limited, configuration entirely on the command line, obviating the need for a configuration file. This may be particularly useful when the local host is to be configured as a broadcast/multicast client, with all peers being determined by listening to broadcasts at run time. .Pp If NetInfo support is built into .Nm , then .Nm will attempt to read its configuration from the NetInfo if the default .Xr ntp.conf 5 file cannot be read and no file is specified by the .Fl c option. .Pp Various internal .Nm variables can be displayed and configuration options altered while the .Nm is running using the .Xr ntpq 8 and .Xr ntpdc 8 utility programs. .Pp When .Nm starts it looks at the value of .Xr umask 2 , and if zero .Nm will set the .Xr umask 2 to 022. .Sh "OPTIONS" .Bl -tag .It Fl 4 , Fl \-ipv4 Force IPv4 DNS name resolution. This option must not appear in combination with any of the following options: ipv6. .sp Force DNS resolution of following host names on the command line to the IPv4 namespace. .It Fl 6 , Fl \-ipv6 Force IPv6 DNS name resolution. This option must not appear in combination with any of the following options: ipv4. .sp Force DNS resolution of following host names on the command line to the IPv6 namespace. .It Fl a , Fl \-authreq Require crypto authentication. This option must not appear in combination with any of the following options: authnoreq. .sp Require cryptographic authentication for broadcast client, multicast client and symmetric passive associations. This is the default. .It Fl A , Fl \-authnoreq Do not require crypto authentication. This option must not appear in combination with any of the following options: authreq. .sp Do not require cryptographic authentication for broadcast client, multicast client and symmetric passive associations. This is almost never a good idea. .It Fl b , Fl \-bcastsync Allow us to sync to broadcast servers. .sp .It Fl c Ar string , Fl \-configfile Ns = Ns Ar string configuration file name. .sp The name and path of the configuration file, \fI/etc/ntp.conf\fP by default. .It Fl d , Fl \-debug\-level Increase debug verbosity level. This option may appear an unlimited number of times. .sp .It Fl D Ar number , Fl \-set\-debug\-level Ns = Ns Ar number Set the debug verbosity level. This option may appear an unlimited number of times. This option takes an integer number as its argument. .sp .It Fl f Ar string , Fl \-driftfile Ns = Ns Ar string frequency drift file name. .sp The name and path of the frequency file, \fI/etc/ntp.drift\fP by default. This is the same operation as the \fBdriftfile\fP \fIdriftfile\fP configuration specification in the \fI/etc/ntp.conf\fP file. .It Fl g , Fl \-panicgate Allow the first adjustment to be Big. This option may appear an unlimited number of times. .sp Normally, \fBntpd\fP exits with a message to the system log if the offset exceeds the panic threshold, which is 1000 s by default. This option allows the time to be set to any value without restriction; however, this can happen only once. If the threshold is exceeded after that, \fBntpd\fP will exit with a message to the system log. This option can be used with the \fB\-q\fP and \fB\-x\fP options. See the \fBtinker\fP configuration file directive for other options. .It Fl G , Fl \-force\-step\-once Step any initial offset correction.. .sp Normally, \fBntpd\fP steps the time if the time offset exceeds the step threshold, which is 128 ms by default, and otherwise slews the time. This option forces the initial offset correction to be stepped, so the highest time accuracy can be achieved quickly. However, this may also cause the time to be stepped back so this option must not be used if applications requiring monotonic time are running. See the \fBtinker\fP configuration file directive for other options. .It Fl i Ar string , Fl \-jaildir Ns = Ns Ar string Jail directory. .sp Chroot the server to the directory \fIjaildir\fP . This option also implies that the server attempts to drop root privileges at startup. You may need to also specify a \fB\-u\fP option. This option is only available if the OS supports adjusting the clock without full root privileges. This option is supported under NetBSD (configure with \fB\-\-enable\-clockctl\fP) or Linux (configure with \fB\-\-enable\-linuxcaps\fP) or Solaris (configure with \fB\-\-enable\-solarisprivs\fP). .It Fl I Ar iface , Fl \-interface Ns = Ns Ar iface Listen on an interface name or address. This option may appear an unlimited number of times. .sp Open the network address given, or all the addresses associated with the given interface name. This option may appear multiple times. This option also implies not opening other addresses, except wildcard and localhost. This option is deprecated. Please consider using the configuration file \fBinterface\fP command, which is more versatile. .It Fl k Ar string , Fl \-keyfile Ns = Ns Ar string path to symmetric keys. .sp Specify the name and path of the symmetric key file. \fI/etc/ntp.keys\fP is the default. This is the same operation as the \fBkeys\fP \fIkeyfile\fP configuration file directive. .It Fl l Ar string , Fl \-logfile Ns = Ns Ar string path to the log file. .sp Specify the name and path of the log file. The default is the system log file. This is the same operation as the \fBlogfile\fP \fIlogfile\fP configuration file directive. .It Fl L , Fl \-novirtualips Do not listen to virtual interfaces. .sp Do not listen to virtual interfaces, defined as those with names containing a colon. This option is deprecated. Please consider using the configuration file \fBinterface\fP command, which is more versatile. .It Fl M , Fl \-modifymmtimer Modify Multimedia Timer (Windows only). .sp Set the Windows Multimedia Timer to highest resolution. This ensures the resolution does not change while ntpd is running, avoiding timekeeping glitches associated with changes. .It Fl n , Fl \-nofork Do not fork. This option must not appear in combination with any of the following options: wait\-sync. .sp .It Fl N , Fl \-nice Run at high priority. .sp To the extent permitted by the operating system, run \fBntpd\fP at the highest priority. .It Fl p Ar string , Fl \-pidfile Ns = Ns Ar string path to the PID file. .sp Specify the name and path of the file used to record \fBntpd\fP's process ID. This is the same operation as the \fBpidfile\fP \fIpidfile\fP configuration file directive. .It Fl P Ar number , Fl \-priority Ns = Ns Ar number Process priority. This option takes an integer number as its argument. .sp To the extent permitted by the operating system, run \fBntpd\fP at the specified \fBsched_setscheduler(SCHED_FIFO)\fP priority. .It Fl q , Fl \-quit Set the time and quit. This option must not appear in combination with any of the following options: saveconfigquit, wait\-sync. .sp \fBntpd\fP will not daemonize and will exit after the clock is first synchronized. This behavior mimics that of the \fBntpdate\fP program, which will soon be replaced with a shell script. The \fB\-g\fP and \fB\-x\fP options can be used with this option. Note: The kernel time discipline is disabled with this option. .It Fl r Ar string , Fl \-propagationdelay Ns = Ns Ar string Broadcast/propagation delay. .sp Specify the default propagation delay from the broadcast/multicast server to this client. This is necessary only if the delay cannot be computed automatically by the protocol. .It Fl \-saveconfigquit Ns = Ns Ar string Save parsed configuration and quit. This option must not appear in combination with any of the following options: quit, wait\-sync. .sp Cause \fBntpd\fP to parse its startup configuration file and save an equivalent to the given filename and exit. This option was designed for automated testing. .It Fl s Ar string , Fl \-statsdir Ns = Ns Ar string Statistics file location. .sp Specify the directory path for files created by the statistics facility. This is the same operation as the \fBstatsdir\fP \fIstatsdir\fP configuration file directive. .It Fl t Ar tkey , Fl \-trustedkey Ns = Ns Ar tkey Trusted key number. This option may appear an unlimited number of times. .sp Add the specified key number to the trusted key list. .It Fl u Ar string , Fl \-user Ns = Ns Ar string Run as userid (or userid:groupid). .sp Specify a user, and optionally a group, to switch to. This option is only available if the OS supports adjusting the clock without full root privileges. This option is supported under NetBSD (configure with \fB\-\-enable\-clockctl\fP) or Linux (configure with \fB\-\-enable\-linuxcaps\fP) or Solaris (configure with \fB\-\-enable\-solarisprivs\fP). .It Fl U Ar number , Fl \-updateinterval Ns = Ns Ar number interval in seconds between scans for new or dropped interfaces. This option takes an integer number as its argument. .sp Give the time in seconds between two scans for new or dropped interfaces. For systems with routing socket support the scans will be performed shortly after the interface change has been detected by the system. Use 0 to disable scanning. 60 seconds is the minimum time between scans. .It Fl \-var Ns = Ns Ar nvar make ARG an ntp variable (RW). This option may appear an unlimited number of times. .sp .It Fl \-dvar Ns = Ns Ar ndvar make ARG an ntp variable (RW|DEF). This option may appear an unlimited number of times. .sp .It Fl w Ar number , Fl \-wait\-sync Ns = Ns Ar number Seconds to wait for first clock sync. This option must not appear in combination with any of the following options: nofork, quit, saveconfigquit. This option takes an integer number as its argument. .sp If greater than zero, alters \fBntpd\fP's behavior when forking to daemonize. Instead of exiting with status 0 immediately after the fork, the parent waits up to the specified number of seconds for the child to first synchronize the clock. The exit status is zero (success) if the clock was synchronized, otherwise it is \fBETIMEDOUT\fP. This provides the option for a script starting \fBntpd\fP to easily wait for the first set of the clock before proceeding. .It Fl x , Fl \-slew Slew up to 600 seconds. .sp Normally, the time is slewed if the offset is less than the step threshold, which is 128 ms by default, and stepped if above the threshold. This option sets the threshold to 600 s, which is well within the accuracy window to set the clock manually. Note: Since the slew rate of typical Unix kernels is limited to 0.5 ms/s, each second of adjustment requires an amortization interval of 2000 s. Thus, an adjustment as much as 600 s will take almost 14 days to complete. This option can be used with the \fB\-g\fP and \fB\-q\fP options. See the \fBtinker\fP configuration file directive for other options. Note: The kernel time discipline is disabled with this option. .It Fl \-usepcc Use CPU cycle counter (Windows only). .sp Attempt to substitute the CPU counter for \fBQueryPerformanceCounter\fP. The CPU counter and \fBQueryPerformanceCounter\fP are compared, and if they have the same frequency, the CPU counter (RDTSC on x86) is used directly, saving the overhead of a system call. .It Fl \-pccfreq Ns = Ns Ar string Force CPU cycle counter use (Windows only). .sp Force substitution the CPU counter for \fBQueryPerformanceCounter\fP. The CPU counter (RDTSC on x86) is used unconditionally with the given frequency (in Hz). .It Fl m , Fl \-mdns Register with mDNS as a NTP server. .sp Registers as an NTP server with the local mDNS server which allows the server to be discovered via mDNS client lookup. .It Fl \&? , Fl \-help Display usage information and exit. .It Fl \&! , Fl \-more\-help Pass the extended usage information through a pager. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from environment variables named: .nf \fBNTPD_\fP or \fBNTPD\fP .fi .ad .Sh USAGE .Ss "How NTP Operates" The .Nm utility operates by exchanging messages with one or more configured servers over a range of designated poll intervals. When started, whether for the first or subsequent times, the program requires several exchanges from the majority of these servers so the signal processing and mitigation algorithms can accumulate and groom the data and set the clock. In order to protect the network from bursts, the initial poll interval for each server is delayed an interval randomized over a few seconds. At the default initial poll interval of 64s, several minutes can elapse before the clock is set. This initial delay to set the clock can be safely and dramatically reduced using the .Cm iburst keyword with the .Ic server configuration command, as described in .Xr ntp.conf 5 . .Pp Most operating systems and hardware of today incorporate a time\-of\-year (TOY) chip to maintain the time during periods when the power is off. When the machine is booted, the chip is used to initialize the operating system time. After the machine has synchronized to a NTP server, the operating system corrects the chip from time to time. In the default case, if .Nm detects that the time on the host is more than 1000s from the server time, .Nm assumes something must be terribly wrong and the only reliable action is for the operator to intervene and set the clock by hand. (Reasons for this include there is no TOY chip, or its battery is dead, or that the TOY chip is just of poor quality.) This causes .Nm to exit with a panic message to the system log. The .Fl g option overrides this check and the clock will be set to the server time regardless of the chip time (up to 68 years in the past or future \(em this is a limitation of the NTPv4 protocol). However, and to protect against broken hardware, such as when the CMOS battery fails or the clock counter becomes defective, once the clock has been set an error greater than 1000s will cause .Nm to exit anyway. .Pp Under ordinary conditions, .Nm adjusts the clock in small steps so that the timescale is effectively continuous and without discontinuities. Under conditions of extreme network congestion, the roundtrip delay jitter can exceed three seconds and the synchronization distance, which is equal to one\-half the roundtrip delay plus error budget terms, can become very large. The .Nm algorithms discard sample offsets exceeding 128 ms, unless the interval during which no sample offset is less than 128 ms exceeds 900s. The first sample after that, no matter what the offset, steps the clock to the indicated time. In practice this reduces the false alarm rate where the clock is stepped in error to a vanishingly low incidence. .Pp As the result of this behavior, once the clock has been set it very rarely strays more than 128 ms even under extreme cases of network path congestion and jitter. Sometimes, in particular when .Nm is first started without a valid drift file on a system with a large intrinsic drift the error might grow to exceed 128 ms, which would cause the clock to be set backwards if the local clock time is more than 128 s in the future relative to the server. In some applications, this behavior may be unacceptable. There are several solutions, however. If the .Fl x option is included on the command line, the clock will never be stepped and only slew corrections will be used. But this choice comes with a cost that should be carefully explored before deciding to use the .Fl x option. The maximum slew rate possible is limited to 500 parts\-per\-million (PPM) as a consequence of the correctness principles on which the NTP protocol and algorithm design are based. As a result, the local clock can take a long time to converge to an acceptable offset, about 2,000 s for each second the clock is outside the acceptable range. During this interval the local clock will not be consistent with any other network clock and the system cannot be used for distributed applications that require correctly synchronized network time. .Pp In spite of the above precautions, sometimes when large frequency errors are present the resulting time offsets stray outside the 128\-ms range and an eventual step or slew time correction is required. If following such a correction the frequency error is so large that the first sample is outside the acceptable range, .Nm enters the same state as when the .Pa ntp.drift file is not present. The intent of this behavior is to quickly correct the frequency and restore operation to the normal tracking mode. In the most extreme cases (the host .Cm time.ien.it comes to mind), there may be occasional step/slew corrections and subsequent frequency corrections. It helps in these cases to use the .Cm burst keyword when configuring the server, but ONLY when you have permission to do so from the owner of the target host. .Pp Finally, in the past many startup scripts would run .Xr ntpdate 8 or .Xr sntp 8 to get the system clock close to correct before starting .Xr ntpd 8 , but this was never more than a mediocre hack and is no longer needed. If you are following the instructions in .Sx "Starting NTP (Best Current Practice)" and you still need to set the system time before starting .Nm , please open a bug report and document what is going on, and then look at using .Xr sntp 8 if you really need to set the clock before starting .Nm . .Pp There is a way to start .Xr ntpd 8 that often addresses all of the problems mentioned above. .Ss "Starting NTP (Best Current Practice)" First, use the .Cm iburst option on your .Cm server entries. .Pp If you can also keep a good .Pa ntp.drift file then .Xr ntpd 8 will effectively "warm\-start" and your system's clock will be stable in under 11 seconds' time. .Pp As soon as possible in the startup sequence, start .Xr ntpd 8 with at least the .Fl g and perhaps the .Fl N options. Then, start the rest of your "normal" processes. This will give .Xr ntpd 8 as much time as possible to get the system's clock synchronized and stable. .Pp Finally, if you have processes like .Cm dovecot or database servers that require monotonically\-increasing time, run .Xr ntp\-wait 1ntp\-waitmdoc as late as possible in the boot sequence (perhaps with the .Fl v flag) and after .Xr ntp\-wait 1ntp\-waitmdoc exits successfully it is as safe as it will ever be to start any process that require stable time. .Ss "Frequency Discipline" The .Nm behavior at startup depends on whether the frequency file, usually .Pa ntp.drift , exists. This file contains the latest estimate of clock frequency error. When the .Nm is started and the file does not exist, the .Nm enters a special mode designed to quickly adapt to the particular system clock oscillator time and frequency error. This takes approximately 15 minutes, after which the time and frequency are set to nominal values and the .Nm enters normal mode, where the time and frequency are continuously tracked relative to the server. After one hour the frequency file is created and the current frequency offset written to it. When the .Nm is started and the file does exist, the .Nm frequency is initialized from the file and enters normal mode immediately. After that the current frequency offset is written to the file at hourly intervals. .Ss "Operating Modes" The .Nm utility can operate in any of several modes, including symmetric active/passive, client/server broadcast/multicast and manycast, as described in the .Qq Association Management page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . It normally operates continuously while monitoring for small changes in frequency and trimming the clock for the ultimate precision. However, it can operate in a one\-time mode where the time is set from an external server and frequency is set from a previously recorded frequency file. A broadcast/multicast or manycast client can discover remote servers, compute server\-client propagation delay correction factors and configure itself automatically. This makes it possible to deploy a fleet of workstations without specifying configuration details specific to the local environment. .Pp By default, .Nm runs in continuous mode where each of possibly several external servers is polled at intervals determined by an intricate state machine. The state machine measures the incidental roundtrip delay jitter and oscillator frequency wander and determines the best poll interval using a heuristic algorithm. Ordinarily, and in most operating environments, the state machine will start with 64s intervals and eventually increase in steps to 1024s. A small amount of random variation is introduced in order to avoid bunching at the servers. In addition, should a server become unreachable for some time, the poll interval is increased in steps to 1024s in order to reduce network overhead. .Pp In some cases it may not be practical for .Nm to run continuously. A common workaround has been to run the .Xr ntpdate 8 or .Xr sntp 8 programs from a .Xr cron 8 job at designated times. However, these programs do not have the crafted signal processing, error checking or mitigation algorithms of .Nm . The .Fl q option is intended for this purpose. Setting this option will cause .Nm to exit just after setting the clock for the first time. The procedure for initially setting the clock is the same as in continuous mode; most applications will probably want to specify the .Cm iburst keyword with the .Ic server configuration command. With this keyword a volley of messages are exchanged to groom the data and the clock is set in about 10 s. If nothing is heard after a couple of minutes, the daemon times out and exits. After a suitable period of mourning, the .Xr ntpdate 8 program will be retired. .Pp When kernel support is available to discipline the clock frequency, which is the case for stock Solaris, Tru64, Linux and .Fx , a useful feature is available to discipline the clock frequency. First, .Nm is run in continuous mode with selected servers in order to measure and record the intrinsic clock frequency offset in the frequency file. It may take some hours for the frequency and offset to settle down. Then the .Nm is stopped and run in one\-time mode as required. At each startup, the frequency is read from the file and initializes the kernel frequency. .Ss "Poll Interval Control" This version of NTP includes an intricate state machine to reduce the network load while maintaining a quality of synchronization consistent with the observed jitter and wander. There are a number of ways to tailor the operation in order enhance accuracy by reducing the interval or to reduce network overhead by increasing it. However, the user is advised to carefully consider the consequences of changing the poll adjustment range from the default minimum of 64 s to the default maximum of 1,024 s. The default minimum can be changed with the .Ic tinker .Cm minpoll command to a value not less than 16 s. This value is used for all configured associations, unless overridden by the .Cm minpoll option on the configuration command. Note that most device drivers will not operate properly if the poll interval is less than 64 s and that the broadcast server and manycast client associations will also use the default, unless overridden. .Pp In some cases involving dial up or toll services, it may be useful to increase the minimum interval to a few tens of minutes and maximum interval to a day or so. Under normal operation conditions, once the clock discipline loop has stabilized the interval will be increased in steps from the minimum to the maximum. However, this assumes the intrinsic clock frequency error is small enough for the discipline loop correct it. The capture range of the loop is 500 PPM at an interval of 64s decreasing by a factor of two for each doubling of interval. At a minimum of 1,024 s, for example, the capture range is only 31 PPM. If the intrinsic error is greater than this, the drift file .Pa ntp.drift will have to be specially tailored to reduce the residual error below this limit. Once this is done, the drift file is automatically updated once per hour and is available to initialize the frequency on subsequent daemon restarts. .Ss "The huff\-n'\-puff Filter" In scenarios where a considerable amount of data are to be downloaded or uploaded over telephone modems, timekeeping quality can be seriously degraded. This occurs because the differential delays on the two directions of transmission can be quite large. In many cases the apparent time errors are so large as to exceed the step threshold and a step correction can occur during and after the data transfer is in progress. .Pp The huff\-n'\-puff filter is designed to correct the apparent time offset in these cases. It depends on knowledge of the propagation delay when no other traffic is present. In common scenarios this occurs during other than work hours. The filter maintains a shift register that remembers the minimum delay over the most recent interval measured usually in hours. Under conditions of severe delay, the filter corrects the apparent offset using the sign of the offset and the difference between the apparent delay and minimum delay. The name of the filter reflects the negative (huff) and positive (puff) correction, which depends on the sign of the offset. .Pp The filter is activated by the .Ic tinker command and .Cm huffpuff keyword, as described in .Xr ntp.conf 5 . .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh FILES .Bl -tag -width /etc/ntp.drift -compact .It Pa /etc/ntp.conf the default name of the configuration file .It Pa /etc/ntp.drift the default name of the drift file .It Pa /etc/ntp.keys the default name of the key file .El .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh "SEE ALSO" .Xr ntp.conf 5 , .Xr ntpdate 8 , .Xr ntpdc 8 , .Xr ntpq 8 , .Xr sntp 8 .Pp In addition to the manual pages provided, comprehensive documentation is available on the world wide web at .Li http://www.ntp.org/ . A snapshot of this documentation is available in HTML format in .Pa /usr/share/doc/ntp . .Rs .%A David L. Mills .%T Network Time Protocol (Version 1) .%O RFC1059 .Re .Rs .%A David L. Mills .%T Network Time Protocol (Version 2) .%O RFC1119 .Re .Rs .%A David L. Mills .%T Network Time Protocol (Version 3) .%O RFC1305 .Re .Rs .%A David L. Mills .%A J. Martin, Ed. .%A J. Burbank .%A W. Kasch .%T Network Time Protocol Version 4: Protocol and Algorithms Specification .%O RFC5905 .Re .Rs .%A David L. Mills .%A B. Haberman, Ed. .%T Network Time Protocol Version 4: Autokey Specification .%O RFC5906 .Re .Rs .%A H. Gerstung .%A C. Elliott .%A B. Haberman, Ed. .%T Definitions of Managed Objects for Network Time Protocol Version 4: (NTPv4) .%O RFC5907 .Re .Rs .%A R. Gayraud .%A B. Lourdelet .%T Network Time Protocol (NTP) Server Option for DHCPv6 .%O RFC5908 .Re .Sh "AUTHORS" The University of Delaware and Network Time Foundation .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh BUGS The .Nm utility has gotten rather fat. While not huge, it has gotten larger than might be desirable for an elevated\-priority .Nm running on a workstation, particularly since many of the fancy features which consume the space were designed more with a busy primary server, rather than a high stratum workstation in mind. .Pp Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh NOTES Portions of this document came from FreeBSD. .Pp This manual page was \fIAutoGen\fP\-erated from the \fBntpd\fP option definitions. diff --git a/usr.sbin/ntp/doc/ntpq.8 b/usr.sbin/ntp/doc/ntpq.8 index e6c66ed71d97..21f15926a0ab 100644 --- a/usr.sbin/ntp/doc/ntpq.8 +++ b/usr.sbin/ntp/doc/ntpq.8 @@ -1,1055 +1,1055 @@ .Dd August 14 2018 .Dt NTPQ 8 User Commands .Os .\" EDIT THIS FILE WITH CAUTION (ntpq-opts.mdoc) .\" .\" It has been AutoGen-ed August 14, 2018 at 08:30:05 AM by AutoGen 5.18.5 .\" From the definitions ntpq-opts.def .\" and the template file agmdoc-cmd.tpl .Sh NAME .Nm ntpq -.Nd standard NTP query program +.Nd query Network Time Protocol servers .Sh SYNOPSIS .Nm .\" Mixture of short (flag) options and long options .Op Fl flags .Op Fl flag Op Ar value .Op Fl \-option\-name Ns Oo Oo Ns "=| " Oc Ns Ar value Oc [ host ...] .Pp .Sh DESCRIPTION .Pp The .Nm utility program is used to query NTP servers to monitor NTP operations and performance, requesting information about current state and/or changes in that state. The program may be run either in interactive mode or controlled using command line arguments. Requests to read and write arbitrary variables can be assembled, with raw and pretty\-printed output options being available. The .Nm utility can also obtain and print a list of peers in a common format by sending multiple queries to the server. .Pp If one or more request options is included on the command line when .Nm is executed, each of the requests will be sent to the NTP servers running on each of the hosts given as command line arguments, or on localhost by default. If no request options are given, .Nm will attempt to read commands from the standard input and execute these on the NTP server running on the first host given on the command line, again defaulting to localhost when no other host is specified. The .Nm utility will prompt for commands if the standard input is a terminal device. .Pp .Nm uses NTP mode 6 packets to communicate with the NTP server, and hence can be used to query any compatible server on the network which permits it. Note that since NTP is a UDP protocol this communication will be somewhat unreliable, especially over large distances in terms of network topology. The .Nm utility makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable timeout time. .Pp Note that in contexts where a host name is expected, a .Fl 4 qualifier preceding the host name forces resolution to the IPv4 namespace, while a .Fl 6 qualifier forces resolution to the IPv6 namespace. For examples and usage, see the .Dq NTP Debugging Techniques page. .Pp Specifying a command line option other than .Fl i or .Fl n will cause the specified query (queries) to be sent to the indicated host(s) immediately. Otherwise, .Nm will attempt to read interactive format commands from the standard input. .Ss "Internal Commands" .Pp Interactive format commands consist of a keyword followed by zero to four arguments. Only enough characters of the full keyword to uniquely identify the command need be typed. .Pp A number of interactive format commands are executed entirely within the .Nm utility itself and do not result in NTP requests being sent to a server. These are described following. .Bl -tag -width "help [command]" -compact -offset indent .It Ic ? Op Ar command .It Ic help Op Ar command A .Ql \&? by itself will print a list of all the commands known to .Nm . A .Ql \&? followed by a command name will print function and usage information about the command. .It Ic addvars Ar name Ns Oo \&= Ns Ar value Oc Ns Op ,... .It Ic rmvars Ar name Ns Op ,... .It Ic clearvars .It Ic showvars The arguments to this command consist of a list of items of the form .Ar name Ns Op \&= Ns Ar value , where the .No \&= Ns Ar value is ignored, and can be omitted, in requests to the server to read variables. The .Nm utility maintains an internal list in which data to be included in messages can be assembled, and displayed or set using the .Ic readlist and .Ic writelist commands described below. The .Ic addvars command allows variables and their optional values to be added to the list. If more than one variable is to be added, the list should be comma\-separated and not contain white space. The .Ic rmvars command can be used to remove individual variables from the list, while the .Ic clearvars command removes all variables from the list. The .Ic showvars command displays the current list of optional variables. .It Ic authenticate Op Cm yes Ns | Ns Cm no Normally .Nm does not authenticate requests unless they are write requests. The command .Ic authenticate Cm yes causes .Nm to send authentication with all requests it makes. Authenticated requests causes some servers to handle requests slightly differently. The command .Ic authenticate causes .Nm to display whether or not it is currently authenticating requests. .It Ic cooked Causes output from query commands to be "cooked", so that variables which are recognized by .Nm will have their values reformatted for human consumption. Variables which .Nm could not decode completely are marked with a trailing .Ql \&? . .It Ic debug Op Cm more Ns | Ns Cm less Ns | Ns Cm off With no argument, displays the current debug level. Otherwise, the debugging level is changed as indicated. .It Ic delay Op Ar milliseconds Specify a time interval to be added to timestamps included in requests which require authentication. This is used to enable (unreliable) server reconfiguration over long delay network paths or between machines whose clocks are unsynchronized. Actually the server does not now require timestamps in authenticated requests, so this command may be obsolete. Without any arguments, displays the current delay. .It Ic drefid Op Cm hash Ns | Ns Cm ipv4 Display refids as IPv4 or hash. Without any arguments, displays whether refids are shown as IPv4 addresses or hashes. .It Ic exit Exit .Nm . .It Ic host Op Ar name Set the host to which future queries will be sent. The .Ar name may be either a host name or a numeric address. Without any arguments, displays the current host. .It Ic hostnames Op Cm yes Ns | Ns Cm no If .Cm yes is specified, host names are printed in information displays. If .Cm no is specified, numeric addresses are printed instead. The default is .Cm yes , unless modified using the command line .Fl n switch. Without any arguments, displays whether host names or numeric addresses are shown. .It Ic keyid Op Ar keyid This command allows the specification of a key number to be used to authenticate configuration requests. This must correspond to the .Cm controlkey key number the server has been configured to use for this purpose. Without any arguments, displays the current .Ar keyid . .It Ic keytype Op Ar digest Specify the digest algorithm to use for authenticating requests, with default .Cm MD5 . If .Nm was built with OpenSSL support, and OpenSSL is installed, .Ar digest can be any message digest algorithm supported by OpenSSL. If no argument is given, the current .Ic keytype Ar digest algorithm used is displayed. .It Ic ntpversion Op Cm 1 Ns | Ns Cm 2 Ns | Ns Cm 3 Ns | Ns Cm 4 Sets the NTP version number which .Nm claims in packets. Defaults to 3, and note that mode 6 control messages (and modes, for that matter) didn't exist in NTP version 1. There appear to be no servers left which demand version 1. With no argument, displays the current NTP version that will be used when communicating with servers. .It Ic passwd This command prompts you to type in a password (which will not be echoed) which will be used to authenticate configuration requests. The password must correspond to the key configured for use by the NTP server for this purpose if such requests are to be successful. .It Ic poll Oo Ar n Oc Op Cm verbose Poll an NTP server in client mode .Ar n times. Poll not implemented yet. .It Ic quit Exit .Nm . .It Ic raw Causes all output from query commands is printed as received from the remote server. The only formating/interpretation done on the data is to transform nonascii data into a printable (but barely understandable) form. .It Ic timeout Op Ar milliseconds Specify a timeout period for responses to server queries. The default is about 5000 milliseconds. Without any arguments, displays the current timeout period. Note that since .Nm retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set. .It Ic version Display the version of the .Nm program. .El .Ss "Control Message Commands" Association ids are used to identify system, peer and clock variables. System variables are assigned an association id of zero and system name space, while each association is assigned a nonzero association id and peer namespace. Most control commands send a single message to the server and expect a single response message. The exceptions are the .Ic peers command, which sends a series of messages, and the .Ic mreadlist and .Ic mreadvar commands, which iterate over a range of associations. .Bl -tag -width "something" -compact -offset indent .It Ic apeers Display a list of peers in the form: .Dl [tally]remote refid assid st t when pool reach delay offset jitter where the output is just like the .Ic peers command except that the .Cm refid is displayed in hex format and the association number is also displayed. .It Ic associations Display a list of mobilized associations in the form: .Dl ind assid status conf reach auth condition last_event cnt .Bl -column -offset indent ".Sy Variable" "see the select field of the peer status word" .It Sy Variable Ta Sy Description .It Cm ind Ta index on this list .It Cm assid Ta association id .It Cm status Ta peer status word .It Cm conf Ta Cm yes : No persistent, Cm no : No ephemeral .It Cm reach Ta Cm yes : No reachable, Cm no : No unreachable .It Cm auth Ta Cm ok , Cm yes , Cm bad No and Cm none .It Cm condition Ta selection status \&(see the Cm select No field of the peer status word\&) .It Cm last_event Ta event report \&(see the Cm event No field of the peer status word\&) .It Cm cnt Ta event count \&(see the Cm count No field of the peer status word\&) .El .It Ic authinfo Display the authentication statistics counters: time since reset, stored keys, free keys, key lookups, keys not found, uncached keys, expired keys, encryptions, decryptions. .It Ic clocklist Op Ar associd .It Ic cl Op Ar associd Display all clock variables in the variable list for those associations supporting a reference clock. .It Ic clockvar Oo Ar associd Oc Oo Ar name Ns Oo \&= Ns Ar value Oc Ns Oc Ns Op ,... .It Ic cv Oo Ar associd Oc Oo Ar name Ns Oo \&= Ns Ar value Oc Ns Oc Ns Op ,... Display a list of clock variables for those associations supporting a reference clock. .It Ic :config Ar "configuration command line" Send the remainder of the command line, including whitespace, to the server as a run\-time configuration command in the same format as a line in the configuration file. This command is experimental until further notice and clarification. Authentication is of course required. .It Ic config\-from\-file Ar filename Send each line of .Ar filename to the server as run\-time configuration commands in the same format as lines in the configuration file. This command is experimental until further notice and clarification. Authentication is required. .It Ic ifstats Display status and statistics counters for each local network interface address: interface number, interface name and address or broadcast, drop, flag, ttl, mc, received, sent, send failed, peers, uptime. Authentication is required. .It Ic iostats Display network and reference clock I/O statistics: time since reset, receive buffers, free receive buffers, used receive buffers, low water refills, dropped packets, ignored packets, received packets, packets sent, packet send failures, input wakeups, useful input wakeups. .It Ic kerninfo Display kernel loop and PPS statistics: associd, status, pll offset, pll frequency, maximum error, estimated error, kernel status, pll time constant, precision, frequency tolerance, pps frequency, pps stability, pps jitter, calibration interval, calibration cycles, jitter exceeded, stability exceeded, calibration errors. As with other ntpq output, times are in milliseconds; very small values may be shown as exponentials. The precision value displayed is in milliseconds as well, unlike the precision system variable. .It Ic lassociations Perform the same function as the associations command, except display mobilized and unmobilized associations, including all clients. .It Ic lopeers Op Fl 4 Ns | Ns Fl 6 Display a list of all peers and clients showing .Cm dstadr (associated with the given IP version). .It Ic lpassociations Display the last obtained list of associations, including all clients. .It Ic lpeers Op Fl 4 Ns | Ns Fl 6 Display a list of all peers and clients (associated with the given IP version). .It Ic monstats Display monitor facility status, statistics, and limits: enabled, addresses, peak addresses, maximum addresses, reclaim above count, reclaim older than, kilobytes, maximum kilobytes. .It Ic mreadlist Ar associdlo Ar associdhi .It Ic mrl Ar associdlo Ar associdhi Perform the same function as the .Ic readlist command for a range of association ids. .It Ic mreadvar Ar associdlo Ar associdhi Oo Ar name Oc Ns Op ,... This range may be determined from the list displayed by any command showing associations. .It Ic mrv Ar associdlo Ar associdhi Oo Ar name Oc Ns Op ,... Perform the same function as the .Ic readvar command for a range of association ids. This range may be determined from the list displayed by any command showing associations. .It Xo Ic mrulist Oo Cm limited | Cm kod | Cm mincount Ns \&= Ns Ar count | .Cm laddr Ns \&= Ns Ar localaddr | Cm sort Ns \&= Ns Oo \&\- Oc Ns Ar sortorder | .Cm resany Ns \&= Ns Ar hexmask | Cm resall Ns \&= Ns Ar hexmask Oc .Xc Display traffic counts of the most recently seen source addresses collected and maintained by the monitor facility. With the exception of .Cm sort Ns \&= Ns Oo \&\- Oc Ns Ar sortorder , the options filter the list returned by .Xr ntpd 8 . The .Cm limited and .Cm kod options return only entries representing client addresses from which the last packet received triggered either discarding or a KoD response. The .Cm mincount Ns = Ns Ar count option filters entries representing less than .Ar count packets. The .Cm laddr Ns = Ns Ar localaddr option filters entries for packets received on any local address other than .Ar localaddr . .Cm resany Ns = Ns Ar hexmask and .Cm resall Ns = Ns Ar hexmask filter entries containing none or less than all, respectively, of the bits in .Ar hexmask , which must begin with .Cm 0x . The .Ar sortorder defaults to .Cm lstint and may be .Cm addr , .Cm avgint , .Cm count , .Cm lstint , or any of those preceded by .Ql \&\- to reverse the sort order. The output columns are: .Bl -tag -width "something" -compact -offset indent .It Column Description .It Ic lstint Interval in seconds between the receipt of the most recent packet from this address and the completion of the retrieval of the MRU list by .Nm . .It Ic avgint Average interval in s between packets from this address. .It Ic rstr Restriction flags associated with this address. Most are copied unchanged from the matching .Ic restrict command, however 0x400 (kod) and 0x20 (limited) flags are cleared unless the last packet from this address triggered a rate control response. .It Ic r Rate control indicator, either a period, .Ic L or .Ic K for no rate control response, rate limiting by discarding, or rate limiting with a KoD response, respectively. .It Ic m Packet mode. .It Ic v Packet version number. .It Ic count Packets received from this address. .It Ic rport Source port of last packet from this address. .It Ic remote address host or DNS name, numeric address, or address followed by claimed DNS name which could not be verified in parentheses. .El .It Ic opeers Op Fl 4 | Fl 6 Obtain and print the old\-style list of all peers and clients showing .Cm dstadr (associated with the given IP version), rather than the .Cm refid . .It Ic passociations Perform the same function as the .Ic associations command, except that it uses previously stored data rather than making a new query. .It Ic peers Display a list of peers in the form: .Dl [tally]remote refid st t when pool reach delay offset jitter .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm [tally] single\-character code indicating current value of the .Ic select field of the .Lk decode.html#peer "peer status word" .It Cm remote host name (or IP number) of peer. The value displayed will be truncated to 15 characters unless the .Nm .Fl w option is given, in which case the full value will be displayed on the first line, and if too long, the remaining data will be displayed on the next line. .It Cm refid source IP address or .Lk decode.html#kiss "'kiss code" .It Cm st stratum: 0 for local reference clocks, 1 for servers with local reference clocks, ..., 16 for unsynchronized server clocks .It Cm t .Ic u : unicast or manycast client, .Ic b : broadcast or multicast client, .Ic p : pool source, .Ic l : local (reference clock), .Ic s : symmetric (peer), .Ic A : manycast server, .Ic B : broadcast server, .Ic M : multicast server .It Cm when time in seconds, minutes, hours, or days since the last packet was received, or .Ql \&\- if a packet has never been received .It Cm poll poll interval (s) .It Cm reach reach shift register (octal) .It Cm delay roundtrip delay .It Cm offset offset of server relative to this host .It Cm jitter offset RMS error estimate. .El .It Ic pstats Ar associd Display the statistics for the peer with the given .Ar associd : associd, status, remote host, local address, time last received, time until next send, reachability change, packets sent, packets received, bad authentication, bogus origin, duplicate, bad dispersion, bad reference time, candidate order. .It Ic readlist Op Ar associd .It Ic rl Op Ar associd Display all system or peer variables. If the .Ar associd is omitted, it is assumed to be zero. .It Ic readvar Op Ar associd Ar name Ns Oo Ns = Ns Ar value Oc Op , ... .It Ic rv Op Ar associd Ar name Ns Oo Ns = Ns Ar value Oc Op , ... Display the specified system or peer variables. If .Ar associd is zero, the variables are from the .Sx System Variables name space, otherwise they are from the .Sx Peer Variables name space. The .Ar associd is required, as the same name can occur in both spaces. If no .Ar name is included, all operative variables in the name space are displayed. In this case only, if the .Ar associd is omitted, it is assumed to be zero. Multiple names are specified with comma separators and without whitespace. Note that time values are represented in milliseconds and frequency values in parts\-per\-million (PPM). Some NTP timestamps are represented in the format .Ar YYYY Ns Ar MM Ar DD Ar TTTT , where .Ar YYYY is the year, .Ar MM the month of year, .Ar DD the day of month and .Ar TTTT the time of day. .It Ic reslist Display the access control (restrict) list for .Nm . Authentication is required. .It Ic saveconfig Ar filename Save the current configuration, including any runtime modifications made by .Ic :config or .Ic config\-from\-file , to the NTP server host file .Ar filename . This command will be rejected by the server unless .Lk miscopt.html#saveconfigdir "saveconfigdir" appears in the .Xr ntpd 8 configuration file. .Ar filename can use .Xr date 1 format specifiers to substitute the current date and time, for example, .D1 Ic saveconfig Pa ntp\-%Y%m%d\-%H%M%S.conf . The filename used is stored in system variable .Cm savedconfig . Authentication is required. .It Ic sysinfo Display system operational summary: associd, status, system peer, system peer mode, leap indicator, stratum, log2 precision, root delay, root dispersion, reference id, reference time, system jitter, clock jitter, clock wander, broadcast delay, symm. auth. delay. .It Ic sysstats Display system uptime and packet counts maintained in the protocol module: uptime, sysstats reset, packets received, current version, older version, bad length or format, authentication failed, declined, restricted, rate limited, KoD responses, processed for time. .It Ic timerstats Display interval timer counters: time since reset, timer overruns, calls to transmit. .It Ic writelist Ar associd Set all system or peer variables included in the variable list. .It Ic writevar Ar associd Ar name Ns = Ns Ar value Op , ... Set the specified variables in the variable list. If the .Ar associd is zero, the variables are from the .Sx System Variables name space, otherwise they are from the .Sx Peer Variables name space. The .Ar associd is required, as the same name can occur in both spaces. Authentication is required. .El .Ss Status Words and Kiss Codes The current state of the operating program is shown in a set of status words maintained by the system. Status information is also available on a per\-association basis. These words are displayed by the .Ic readlist and .Ic associations commands both in hexadecimal and in decoded short tip strings. The codes, tips and short explanations are documented on the .Lk decode.html "Event Messages and Status Words" page. The page also includes a list of system and peer messages, the code for the latest of which is included in the status word. .Pp Information resulting from protocol machine state transitions is displayed using an informal set of ASCII strings called .Lk decode.html#kiss "kiss codes" . The original purpose was for kiss\-o'\-death (KoD) packets sent by the server to advise the client of an unusual condition. They are now displayed, when appropriate, in the reference identifier field in various billboards. .Ss System Variables The following system variables appear in the .Ic readlist billboard. Not all variables are displayed in some configurations. .Pp .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm status .Lk decode.html#sys "system status word" .It Cm version NTP software version and build time .It Cm processor hardware platform and version .It Cm system operating system and version .It Cm leap leap warning indicator (0\-3) .It Cm stratum stratum (1\-15) .It Cm precision precision (log2 s) .It Cm rootdelay total roundtrip delay to the primary reference clock .It Cm rootdisp total dispersion to the primary reference clock .It Cm refid reference id or .Lk decode.html#kiss "kiss code" .It Cm reftime reference time .It Ic clock date and time of day .It Cm peer system peer association id .It Cm tc time constant and poll exponent (log2 s) (3\-17) .It Cm mintc minimum time constant (log2 s) (3\-10) .It Cm offset combined offset of server relative to this host .It Cm frequency frequency drift (PPM) relative to hardware clock .It Cm sys_jitter combined system jitter .It Cm clk_wander clock frequency wander (PPM) .It Cm clk_jitter clock jitter .It Cm tai TAI\-UTC offset (s) .It Cm leapsec NTP seconds when the next leap second is/was inserted .It Cm expire NTP seconds when the NIST leapseconds file expires .El The jitter and wander statistics are exponentially\-weighted RMS averages. The system jitter is defined in the NTPv4 specification; the clock jitter statistic is computed by the clock discipline module. .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional system variables are displayed, including some or all of the following, depending on the particular Autokey dance: .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm host Autokey host name for this host .It Cm ident Autokey group name for this host .It Cm flags host flags (see Autokey specification) .It Cm digest OpenSSL message digest algorithm .It Cm signature OpenSSL digest/signature scheme .It Cm update NTP seconds at last signature update .It Cm cert certificate subject, issuer and certificate flags .It Cm until NTP seconds when the certificate expires .El .Ss Peer Variables The following peer variables appear in the .Ic readlist billboard for each association. Not all variables are displayed in some configurations. .Pp .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm associd association id .It Cm status .Lk decode.html#peer "peer status word" .It Cm srcadr source (remote) IP address .It Cm srcport source (remote) port .It Cm dstadr destination (local) IP address .It Cm dstport destination (local) port .It Cm leap leap indicator (0\-3) .It Cm stratum stratum (0\-15) .It Cm precision precision (log2 s) .It Cm rootdelay total roundtrip delay to the primary reference clock .It Cm rootdisp total root dispersion to the primary reference clock .It Cm refid reference id or .Lk decode.html#kiss "kiss code" .It Cm reftime reference time .It Cm rec last packet received time .It Cm reach reach register (octal) .It Cm unreach unreach counter .It Cm hmode host mode (1\-6) .It Cm pmode peer mode (1\-5) .It Cm hpoll host poll exponent (log2 s) (3\-17) .It Cm ppoll peer poll exponent (log2 s) (3\-17) .It Cm headway headway (see .Lk rate.html "Rate Management and the Kiss\-o'\-Death Packet" ) .It Cm flash .Lk decode.html#flash "flash status word" .It Cm keyid symmetric key id .It Cm offset filter offset .It Cm delay filter delay .It Cm dispersion filter dispersion .It Cm jitter filter jitter .It Cm bias unicast/broadcast bias .It Cm xleave interleave delay (see .Lk xleave.html "NTP Interleaved Modes" ) .El The .Cm bias variable is calculated when the first broadcast packet is received after the calibration volley. It represents the offset of the broadcast subgraph relative to the unicast subgraph. The .Cm xleave variable appears only for the interleaved symmetric and interleaved modes. It represents the internal queuing, buffering and transmission delays for the preceding packet. .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional peer variables are displayed, including the following: .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm flags peer flags (see Autokey specification) .It Cm host Autokey server name .It Cm flags peer flags (see Autokey specification) .It Cm signature OpenSSL digest/signature scheme .It Cm initsequence initial key id .It Cm initkey initial key index .It Cm timestamp Autokey signature timestamp .It Cm ident Autokey group name for this association .El .Ss Clock Variables The following clock variables appear in the .Ic clocklist billboard for each association with a reference clock. Not all variables are displayed in some configurations. .Bl -tag -width "something" -compact -offset indent .It Variable Description .It Cm associd association id .It Cm status .Lk decode.html#clock "clock status word" .It Cm device device description .It Cm timecode ASCII time code string (specific to device) .It Cm poll poll messages sent .It Cm noreply no reply .It Cm badformat bad format .It Cm baddata bad date or time .It Cm fudgetime1 fudge time 1 .It Cm fudgetime2 fudge time 2 .It Cm stratum driver stratum .It Cm refid driver reference id .It Cm flags driver flags .El .Sh "OPTIONS" .Bl -tag .It Fl 4 , Fl \-ipv4 Force IPv4 name resolution. This option must not appear in combination with any of the following options: ipv6. .sp Force resolution of following host names on the command line to the IPv4 namespace. .It Fl 6 , Fl \-ipv6 Force IPv6 name resolution. This option must not appear in combination with any of the following options: ipv4. .sp Force resolution of following host names on the command line to the IPv6 namespace. .It Fl c Ar cmd , Fl \-command Ns = Ns Ar cmd run a command and exit. This option may appear an unlimited number of times. .sp The following argument is interpreted as an interactive format command and is added to the list of commands to be executed on the specified host(s). .It Fl d , Fl \-debug\-level Increase debug verbosity level. This option may appear an unlimited number of times. .sp .It Fl D Ar number , Fl \-set\-debug\-level Ns = Ns Ar number Set the debug verbosity level. This option may appear an unlimited number of times. This option takes an integer number as its argument. .sp .It Fl i , Fl \-interactive Force ntpq to operate in interactive mode. This option must not appear in combination with any of the following options: command, peers. .sp Force \fBntpq\fP to operate in interactive mode. Prompts will be written to the standard output and commands read from the standard input. .It Fl n , Fl \-numeric numeric host addresses. .sp Output all host addresses in dotted\-quad numeric format rather than converting to the canonical host names. .It Fl \-old\-rv Always output status line with readvar. .sp By default, \fBntpq\fP now suppresses the \fBassocid=...\fP line that precedes the output of \fBreadvar\fP (alias \fBrv\fP) when a single variable is requested, such as \fBntpq \-c "rv 0 offset"\fP. This option causes \fBntpq\fP to include both lines of output for a single\-variable \fBreadvar\fP. Using an environment variable to preset this option in a script will enable both older and newer \fBntpq\fP to behave identically in this regard. .It Fl p , Fl \-peers Print a list of the peers. This option must not appear in combination with any of the following options: interactive. .sp Print a list of the peers known to the server as well as a summary of their state. This is equivalent to the 'peers' interactive command. .It Fl r Ar keyword , Fl \-refid Ns = Ns Ar keyword Set default display type for S2+ refids. This option takes a keyword as its argument. The argument sets an enumeration value that can be tested by comparing them against the option value macro. The available keywords are: .in +4 .nf .na hash ipv4 .fi or their numeric equivalent. .in -4 .sp The default .Ar keyword for this option is: .ti +4 ipv4 .sp Set the default display format for S2+ refids. .It Fl w , Fl \-wide Display the full 'remote' value. .sp Display the full value of the 'remote' value. If this requires more than 15 characters, display the full value, emit a newline, and continue the data display properly indented on the next line. .It Fl \&? , Fl \-help Display usage information and exit. .It Fl \&! , Fl \-more\-help Pass the extended usage information through a pager. .It Fl > Oo Ar cfgfile Oc , Fl \-save\-opts Oo Ns = Ns Ar cfgfile Oc Save the option state to \fIcfgfile\fP. The default is the \fIlast\fP configuration file listed in the \fBOPTION PRESETS\fP section, below. The command will exit after updating the config file. .It Fl < Ar cfgfile , Fl \-load\-opts Ns = Ns Ar cfgfile , Fl \-no\-load\-opts Load options from \fIcfgfile\fP. The \fIno\-load\-opts\fP form will disable the loading of earlier config/rc/ini files. \fI\-\-no\-load\-opts\fP is handled early, out of order. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from configuration ("RC" or ".INI") file(s) and values from environment variables named: .nf \fBNTPQ_\fP or \fBNTPQ\fP .fi .ad The environmental presets take precedence (are processed later than) the configuration files. The \fIhomerc\fP files are "\fI$HOME\fP", and "\fI.\fP". If any of these are directories, then the file \fI.ntprc\fP is searched for within those directories. .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh "FILES" See \fBOPTION PRESETS\fP for configuration files. .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 66 " (EX_NOINPUT)" A specified configuration file could not be loaded. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh "AUTHORS" The University of Delaware and Network Time Foundation .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh "BUGS" Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh "NOTES" This manual page was \fIAutoGen\fP\-erated from the \fBntpq\fP option definitions. diff --git a/usr.sbin/ntp/doc/sntp.8 b/usr.sbin/ntp/doc/sntp.8 index 94c3c2816035..4509b6efa222 100644 --- a/usr.sbin/ntp/doc/sntp.8 +++ b/usr.sbin/ntp/doc/sntp.8 @@ -1,317 +1,317 @@ .Dd August 14 2018 .Dt SNTP 8 User Commands .Os .\" EDIT THIS FILE WITH CAUTION (sntp-opts.mdoc) .\" .\" It has been AutoGen-ed August 14, 2018 at 08:27:40 AM by AutoGen 5.18.5 .\" From the definitions sntp-opts.def .\" and the template file agmdoc-cmd.tpl .Sh NAME .Nm sntp -.Nd standard Simple Network Time Protocol client program +.Nd reference Simple Network Time Protocol client .Sh SYNOPSIS .Nm .\" Mixture of short (flag) options and long options .Op Fl flags .Op Fl flag Op Ar value .Op Fl \-option\-name Ns Oo Oo Ns "=| " Oc Ns Ar value Oc [ hostname\-or\-IP ...] .Pp .Sh DESCRIPTION .Nm can be used as an SNTP client to query a NTP or SNTP server and either display the time or set the local system's time (given suitable privilege). It can be run as an interactive command or from a .Ic cron job. NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol) are defined and described by RFC 5905. .Pp The default is to write the estimated correct local date and time (i.e. not UTC) to the standard output in a format like: .Ic "'1996\-10\-15 20:17:25.123 (+0800) +4.567 +/\- 0.089 [host] IP sN'" where the .Ic "'(+0800)'" means that to get to UTC from the reported local time one must add 8 hours and 0 minutes, the .Ic "'+4.567'" indicates the local clock is 4.567 seconds behind the correct time (so 4.567 seconds must be added to the local clock to get it to be correct). Note that the number of decimals printed for this value will change based on the reported precision of the server. .Ic "'+/\- 0.089'" is the reported .Em synchronization distance (in seconds), which represents the maximum error due to all causes. If the server does not report valid data needed to calculate the synchronization distance, this will be reported as .Ic "'+/\- ?'" . If the .Em host is different from the .Em IP , both will be displayed. Otherwise, only the .Em IP is displayed. Finally, the .Em stratum of the host is reported and the leap indicator is decoded and displayed. .Sh "OPTIONS" .Bl -tag .It Fl 4 , Fl \-ipv4 Force IPv4 DNS name resolution. This option must not appear in combination with any of the following options: ipv6. .sp Force DNS resolution of the following host names on the command line to the IPv4 namespace. .It Fl 6 , Fl \-ipv6 Force IPv6 DNS name resolution. This option must not appear in combination with any of the following options: ipv4. .sp Force DNS resolution of the following host names on the command line to the IPv6 namespace. .It Fl a Ar auth\-keynumber , Fl \-authentication Ns = Ns Ar auth\-keynumber Enable authentication with the key \fBauth\-keynumber\fP. This option takes an integer number as its argument. .sp Enable authentication using the key specified in this option's argument. The argument of this option is the \fBkeyid\fP, a number specified in the \fBkeyfile\fP as this key's identifier. See the \fBkeyfile\fP option (\fB\-k\fP) for more details. .It Fl b Ar broadcast\-address , Fl \-broadcast Ns = Ns Ar broadcast\-address Listen to the address specified for broadcast time sync. This option may appear an unlimited number of times. .sp If specified \fBsntp\fP will listen to the specified address for NTP broadcasts. The default maximum wait time can (and probably should) be modified with \fB\-t\fP. .It Fl c Ar host\-name , Fl \-concurrent Ns = Ns Ar host\-name Concurrently query all IPs returned for host\-name. This option may appear an unlimited number of times. .sp Requests from an NTP "client" to a "server" should never be sent more rapidly than one every 2 seconds. By default, any IPs returned as part of a DNS lookup are assumed to be for a single instance of \fBntpd\fP, and therefore \fBsntp\fP will send queries to these IPs one after another, with a 2\-second gap in between each query. .sp The \fB\-c\fP or \fB\-\-concurrent\fP flag says that any IPs returned for the DNS lookup of the supplied host\-name are on different machines, so we can send concurrent queries. .It Fl d , Fl \-debug\-level Increase debug verbosity level. This option may appear an unlimited number of times. .sp .It Fl D Ar number , Fl \-set\-debug\-level Ns = Ns Ar number Set the debug verbosity level. This option may appear an unlimited number of times. This option takes an integer number as its argument. .sp .It Fl g Ar milliseconds , Fl \-gap Ns = Ns Ar milliseconds The gap (in milliseconds) between time requests. This option takes an integer number as its argument. The default .Ar milliseconds for this option is: .ti +4 50 .sp Since we're only going to use the first valid response we get and there is benefit to specifying a good number of servers to query, separate the queries we send out by the specified number of milliseconds. .It Fl K Ar file\-name , Fl \-kod Ns = Ns Ar file\-name KoD history filename. The default .Ar file\-name for this option is: .ti +4 /var/db/ntp\-kod .sp Specifies the filename to be used for the persistent history of KoD responses received from servers. If the file does not exist, a warning message will be displayed. The file will not be created. .It Fl k Ar file\-name , Fl \-keyfile Ns = Ns Ar file\-name Look in this file for the key specified with \fB\-a\fP. The default .Ar file\-name for this option is: .ti +4 /etc/ntp.keys .sp This option specifies the keyfile. \fBsntp\fP will search for the key specified with \fB\-a\fP \fIkeyno\fP in this file. See \fBntp.keys(5)\fP for more information. .It Fl l Ar file\-name , Fl \-logfile Ns = Ns Ar file\-name Log to specified logfile. .sp This option causes the client to write log messages to the specified \fIlogfile\fP. .It Fl M Ar number , Fl \-steplimit Ns = Ns Ar number Adjustments less than \fBsteplimit\fP msec will be slewed. This option takes an integer number as its argument. The value of .Ar number is constrained to being: .in +4 .nf .na greater than or equal to 0 .fi .in -4 .sp If the time adjustment is less than \fIsteplimit\fP milliseconds, slew the amount using \fBadjtime(2)\fP. Otherwise, step the correction using \fBsettimeofday(2)\fP. The default value is 0, which means all adjustments will be stepped. This is a feature, as different situations demand different values. .It Fl o Ar number , Fl \-ntpversion Ns = Ns Ar number Send \fBint\fP as our NTP protocol version. This option takes an integer number as its argument. The value of .Ar number is constrained to being: .in +4 .nf .na in the range 0 through 7 .fi .in -4 The default .Ar number for this option is: .ti +4 4 .sp When sending requests to a remote server, tell them we are running NTP protocol version \fIntpversion\fP . .It Fl r , Fl \-usereservedport Use the NTP Reserved Port (port 123). .sp Use port 123, which is reserved for NTP, for our network communications. .It Fl S , Fl \-step OK to 'step' the time with \fBsettimeofday(2)\fP. .sp .It Fl s , Fl \-slew OK to 'slew' the time with \fBadjtime(2)\fP. .sp .It Fl t Ar seconds , Fl \-timeout Ns = Ns Ar seconds The number of seconds to wait for responses. This option takes an integer number as its argument. The default .Ar seconds for this option is: .ti +4 5 .sp When waiting for a reply, \fBsntp\fP will wait the number of seconds specified before giving up. The default should be more than enough for a unicast response. If \fBsntp\fP is only waiting for a broadcast response a longer timeout is likely needed. .It Fl \-wait , Fl \-no\-wait Wait for pending replies (if not setting the time). The \fIno\-wait\fP form will disable the option. This option is enabled by default. .sp If we are not setting the time, wait for all pending responses. .It Fl \&? , Fl \-help Display usage information and exit. .It Fl \&! , Fl \-more\-help Pass the extended usage information through a pager. .It Fl > Oo Ar cfgfile Oc , Fl \-save\-opts Oo Ns = Ns Ar cfgfile Oc Save the option state to \fIcfgfile\fP. The default is the \fIlast\fP configuration file listed in the \fBOPTION PRESETS\fP section, below. The command will exit after updating the config file. .It Fl < Ar cfgfile , Fl \-load\-opts Ns = Ns Ar cfgfile , Fl \-no\-load\-opts Load options from \fIcfgfile\fP. The \fIno\-load\-opts\fP form will disable the loading of earlier config/rc/ini files. \fI\-\-no\-load\-opts\fP is handled early, out of order. .It Fl \-version Op Brq Ar v|c|n Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice. .El .Sh "OPTION PRESETS" Any option that is not marked as \fInot presettable\fP may be preset by loading values from configuration ("RC" or ".INI") file(s) and values from environment variables named: .nf \fBSNTP_\fP or \fBSNTP\fP .fi .ad The environmental presets take precedence (are processed later than) the configuration files. The \fIhomerc\fP files are "\fI$HOME\fP", and "\fI.\fP". If any of these are directories, then the file \fI.ntprc\fP is searched for within those directories. .Sh USAGE .Bl -tag -width indent .It Li "sntp ntpserver.somewhere" is the simplest use of this program and can be run as an unprivileged command to check the current time and error in the local clock. .It Li "sntp \-Ss \-M 128 ntpserver.somewhere" With suitable privilege, run as a command or from a .Xr cron 8 job, .Ic "sntp \-Ss \-M 128 ntpserver.somewhere" will request the time from the server, and if that server reports that it is synchronized then if the offset adjustment is less than 128 milliseconds the correction will be slewed, and if the correction is more than 128 milliseconds the correction will be stepped. .It Li "sntp \-S ntpserver.somewhere" With suitable privilege, run as a command or from a .Xr cron 8 job, .Ic "sntp \-S ntpserver.somewhere" will set (step) the local clock from a synchronized specified server, like the (deprecated) .Xr ntpdate 8 , or .Xr rdate 8 commands. .El .Sh "ENVIRONMENT" See \fBOPTION PRESETS\fP for configuration environment variables. .Sh "FILES" See \fBOPTION PRESETS\fP for configuration files. .Sh "EXIT STATUS" One of the following exit values will be returned: .Bl -tag .It 0 " (EXIT_SUCCESS)" Successful program execution. .It 1 " (EXIT_FAILURE)" The operation failed or the command syntax was not valid. .It 66 " (EX_NOINPUT)" A specified configuration file could not be loaded. .It 70 " (EX_SOFTWARE)" libopts had an internal operational error. Please report it to autogen\-users@lists.sourceforge.net. Thank you. .El .Sh AUTHORS .An "Johannes Maximilian Kuehn" .An "Harlan Stenn" .An "Dave Hart" .Sh "COPYRIGHT" Copyright (C) 1992\-2017 The University of Delaware and Network Time Foundation all rights reserved. This program is released under the terms of the NTP license, . .Sh "BUGS" Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org .Sh "NOTES" This manual page was \fIAutoGen\fP\-erated from the \fBsntp\fP option definitions.