Setup a VLAN on a Linux network interface

This tutorial shows how to setup a virtual interface in Ubuntu. This is particularly useful when you need a specific interface (like ethernet) to have two different IP addresses on two different subnets (to connect to a lidar, for instance).

add a VLAN interface:

sudo ip link add link eth0 name eth0.14 type vlan id 14

Verify that a new file was created in /proc/net/vlan

sudo cat /proc/net/vlan/th0.14

sudo nmcli connection add type vlan con-name lidar ifname th0.14 dev eth0 id 14 ip4 192.168.1.102/24

Bring it up

sudo nmcli connection up lidar

If needed, bring it down or remove it with

sudo nmcli connection down lidar

This brings it down permanently (doesn't start after reboot)

sudo nmcli connection modify lidar connection.autoconnect no

sudo nmcli connection delete lidar