Adding a VLAN Interface
To add a VLAN interface to a
router, use the following command:
configure
isis add [vlan
all | {vlan} vlan_name] area
area_name {ipv4 | ipv6}

Note
The interface is not enabled separately from the area. If the area is enabled, the interface will begin transmitting hellos as soon as this command is executed, provided the interface is in forwarding mode and has active links.