A vlan is an OSI layer 2 method to provide multiple logical networks to exist on a single physical network. Vlan trunking can be a useful tool for a server to exist on multiple networks without the additional overhead and expense of additional physical interfaces.
This guide describes how to simply setup subinterfaces - virtual interfaces which provide access to the VLan - in CentOS 7.
Method 1 - ifcfg files
First - run
ip link to find the name of the interface. In our case, we have enp0s25.
Next, take the name of the interface, and setup the subinterface file at the following path:
Often, there is a version of this file already in place without the vlan id you can use as a basis.
Create the file similar to this:
VLAN=yes DEVICE=[interface].[vlan] ONBOOT=yes BOOTPROTO=static IPADDR=192.168.10.1 NETMASK=255.255.255.0
Finally, restart networking:
$ sudo systemctl restart network
Method 2 - ip cli
This same task can also be accomplished using the
ip command. To add
vlan 43 to
eth0, you will create the interface
$ sudo ip link add link eth0 name eth0.43 type vlan id 43 $ ip link set dev eth0.43 up
And to delete the vlan interface:
$ sudo ip link delete eth0.43