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| Show First 20 Lines • Show All 5,219 Lines • ▼ Show 20 Lines | <sect1 xml:id="network-vlan"> | ||||
| <indexterm> | <indexterm> | ||||
| <primary><acronym>VLANs</acronym></primary> | <primary><acronym>VLANs</acronym></primary> | ||||
| </indexterm> | </indexterm> | ||||
| <indexterm> | <indexterm> | ||||
| <primary>Virtual LANs</primary> | <primary>Virtual LANs</primary> | ||||
| </indexterm> | </indexterm> | ||||
| <para><acronym>VLANs</acronym> are a way of virtually dividing up | <para><acronym>VLANs</acronym> are a way of virtually dividing up | ||||
| a network into many different subnetworks. Each will have its | a network into many different subnetworks, also referred | ||||
| own broadcast domain and be isolated from the rest of the | to as segmenting. Each segment will have its | ||||
| own broadcast domain and be isolated from other | |||||
| <acronym>VLANs</acronym>.</para> | <acronym>VLANs</acronym>.</para> | ||||
| <para>On &os;, <acronym>VLANs</acronym> must be supported by the | <para>On &os;, <acronym>VLANs</acronym> must be supported by the | ||||
| network card driver. To see which drivers support vlans, refer | network card driver. To see which drivers support vlans, refer | ||||
| to the &man.vlan.4; manual page.</para> | to the &man.vlan.4; manual page.</para> | ||||
| <para>When configuring a <acronym>VLAN</acronym>, a couple pieces | <para>When configuring a <acronym>VLAN</acronym>, a couple pieces | ||||
| of information must be known. First, which network interface? | of information must be known. First, which network interface? | ||||
| Second, what is the <acronym>VLAN</acronym> tag?</para> | Second, what is the <acronym>VLAN</acronym> tag?</para> | ||||
| <para>To configure <acronym>VLANs</acronym> at run time, with a | <para>To configure <acronym>VLANs</acronym> at run time, with a | ||||
| <acronym>NIC</acronym> of <literal>em0</literal> and a | <acronym>NIC</acronym> of <literal>em0</literal> and a | ||||
| <acronym>VLAN</acronym> tag of <systemitem>5</systemitem>. The | <acronym>VLAN</acronym> tag of <systemitem>5</systemitem> the | ||||
| command would look like this:</para> | command would look like this:</para> | ||||
| <screen>&prompt.root; <userinput>ifconfig <replaceable>em0.5</replaceable> create vlan <replaceable>5</replaceable> vlandev <replaceable>em0</replaceable> inet 192.168.20.20/24</userinput></screen> | <screen>&prompt.root; <userinput>ifconfig <replaceable>em0.5</replaceable> create vlan <replaceable>5</replaceable> vlandev <replaceable>em0</replaceable> inet 192.168.20.20/24</userinput></screen> | ||||
| <note> | <note> | ||||
| <para>See how the interface name includes the | <para>See how the interface name includes the | ||||
| <acronym>NIC</acronym> driver name and the | <acronym>NIC</acronym> driver name and the | ||||
| <acronym>VLAN</acronym> tag, separated by a period? This is a | <acronym>VLAN</acronym> tag, separated by a period? This is a | ||||
| Show All 10 Lines | present on a machine.</para> | ||||
| <programlisting>vlans_<replaceable>em0</replaceable>="<replaceable>5</replaceable>" | <programlisting>vlans_<replaceable>em0</replaceable>="<replaceable>5</replaceable>" | ||||
| ifconfig_<replaceable>em0</replaceable>_<replaceable>5</replaceable>="inet 192.168.20.20/24"</programlisting> | ifconfig_<replaceable>em0</replaceable>_<replaceable>5</replaceable>="inet 192.168.20.20/24"</programlisting> | ||||
| <para>Additional <acronym>VLANs</acronym> may be added, by simply | <para>Additional <acronym>VLANs</acronym> may be added, by simply | ||||
| adding the tag to the | adding the tag to the | ||||
| <literal>vlans_<replaceable>em0</replaceable></literal> | <literal>vlans_<replaceable>em0</replaceable></literal> | ||||
| field and adding an additional line configuring the network on | field and adding an additional line configuring the network on | ||||
| that <acronym>VLAN</acronym> tag's interface.</para> | that <acronym>VLAN</acronym> tag's interface.</para> | ||||
| <para>It is useful to assign a symbolic name to an interface so | |||||
| that when the associated hardware is changed, only a few | |||||
| configuration variables need to be updated. For example, | |||||
| security cameras need to be run over VLAN 1 on | |||||
| <literal>em0</literal>. Later, if the <literal>em0</literal> | |||||
| card is replaced with a card that uses the &man.ixgb.4; driver, | |||||
| all references to <literal>em0.1</literal> will not have to | |||||
| change to <literal>ixgb0.1</literal>.</para> | |||||
| <para>To configure <acronym>VLAN</acronym> | |||||
| <systemitem>5</systemitem>, on the | |||||
| <acronym>NIC</acronym> <literal>em0</literal>, assign the | |||||
| interface name <literal>cameras</literal>, and assign the | |||||
| interface an IP address of <systemitem | |||||
| class="ipaddress"><replaceable>192.168.20.20</replaceable></systemitem> | |||||
| with a <systemitem class="netmask">24</systemitem>-bit prefix, | |||||
| use this command:</para> | |||||
| <screen>&prompt.root; <userinput>ifconfig <replaceable>em0.5</replaceable> create vlan <replaceable>5</replaceable> vlandev <replaceable>em0</replaceable> name <replaceable>cameras</replaceable> inet <replaceable>192.168.20.20/24</replaceable></userinput></screen> | |||||
| <para>For an interface named <literal>video</literal>, use the | |||||
| following:</para> | |||||
| <screen>&prompt.root; <userinput>ifconfig <replaceable>video.5</replaceable> create vlan <replaceable>5</replaceable> vlandev <replaceable>video</replaceable> name <replaceable>cameras inet 192.168.20.20/24</replaceable></userinput></screen> | |||||
| <para>To apply the changes at boot time, add the following lines to | |||||
| <filename>/etc/rc.conf</filename>:</para> | |||||
| <programlisting>vlans_<replaceable>video</replaceable>="<replaceable>camera</replaceable>" | |||||
| create_args_<replaceable>camera</replaceable>="vlan <replaceable>5</replaceable>" | |||||
| ifconfig_<replaceable>camera</replaceable>="inet <replaceable>192.168.20.20/24</replaceable>"</programlisting> | |||||
| </sect1> | </sect1> | ||||
| </chapter> | </chapter> | ||||