CONFIGURE 802.1Q VLAN TAGGING USING THE COMMAND LINE
In Red Hat Enterprise Linux 7, the8021qmodule is loaded by default. If necessary, you can make sure that the module is loaded by issuing the following command asroot:
~]#modprobe --first-time 8021qmodprobe: ERROR: could not insert '8021q': Module already in kernel
To display information about the module, issue the following command:
~]$modinfo 8021q
See themodprobe(8)man page for more command options.
7.4.1. Setting Up 802.1Q VLAN Tagging Using ifcfg Files
Configure the parent interface in/etc/sysconfig/network-scripts/ifcfg-ethX, whereXis a unique number corresponding to a specific interface, as follows:
DEVICE=ethX
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
Configure the VLAN interface configuration in the/etc/sysconfig/network-scripts/directory. The configuration file name should be the parent interface plus a.character plus the VLAN ID number. For example, if the VLAN ID is 192, and the parent interface iseth0, then the configuration file name should beifcfg-eth0.192:
DEVICE=ethX.192
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.168.1.1
PREFIX=24
NETWORK=192.168.1.0
VLAN=yes
If there is a need to configure a second VLAN, with for example, VLAN ID 193, on the same interface,eth0, add a new file with the nameeth0.193with the VLAN configuration details.
Restart the networking service in order for the changes to take effect. Asrootissue the following command:
~]#systemctl restart network
7.4.2. Configure 802.1Q VLAN Tagging Using ip Commands
To create an 802.1Q VLAN interface on Ethernet interfaceeth0, with nameVLAN8and ID8, issue a command asrootas follows:
~]#ip link add linketh0nameeth0.8type vlan id 8
To view the VLAN, issue the following command:
~]$ip -d link showeth0.84: eth0.8@eth0: mtu 1500 qdisc noqueue state UP mode DEFAULT link/ether 52:54:00:ce:5f:6c brd ff:ff:ff:ff:ff:ff promiscuity 0 vlan protocol 802.1Q id 8
Note that theiputility interprets the VLAN ID as a hexadecimal value if it is preceded by0xand as an octal value if it has a leading0. This means that in order to assign a VLAN ID with a decimal value of22, you must not add any leading zeros.
To remove the VLAN, issue a command asrootas follows:
~]#ip link deleteeth0.8
