Configuring a VLANIF Interface

Context

A VLANIF interface is a Layer 3 logical interface. After an IP address is assigned, the VLANIF interface enables VLANs to communicate and can have Layer 3 services deployed.

A VLANIF interface goes Up only after the following conditions are met:

The corresponding VLAN must have been created.
A physical interface or Eth-Trunk in Up state has been added to the corresponding VLAN.

Procedure

Run system-view

The system view is displayed.
Run interface vlanif vlan-id

A VLANIF interface is created and the VLANIF interface view is displayed.
Run ip address ip-address { mask | mask-length } [ sub ]

An IP address is assigned to the VLANIF interface.
(Optional) Run damping time delay-time

The delay after which the VLANIF interface goes Down is set.

By default, the delay is 0 seconds, that is, a VLANIF interface goes Down immediately after the corresponding VLAN goes Down.
Setting a delay after which a VLANIF interface goes Down prevents network flapping caused by status change of the VLANIF interface. This function is also called VLAN damping.

Enable the VLAN damping function on the VLANIF interface. After the last member interface in Up state in the corresponding VLAN goes Down, the VLAN damping-enabled device reports the VLAN Down event to the VLANIF interface after the configured delay. If a member interface in the VLAN goes Up during the delay, the VLANIF interface remains in Up state.
(Optional) Run mtu mtu

The MTU of the VLANIF interface is set.

By default, the MTU of a VLANIF interface is 1500 bytes.

Verifying the Configuration

Run the display interface vlanif vlan-id command to view the status of a VLANIF interface.