1-4z As the default VLAN, VLAN 1 cannot be created or removed.z You cannot manually create or remove VLANs reserved for special purposes.z Dynamic VLANs cannot be removed with the undo vlan command.z A VLAN with a QoS policy applied cannot be removed.z For isolate-user-VLANs or secondary VLANs, if you have used the isolate-user-vlan command tocreate mappings between them, you cannot remove them until you remove the mappings betweenthem first.z A VLAN operating as a probe VLAN for remote port mirroring cannot be removed with the undovlan command. To do that, remove the remote mirroring VLAN configuration from it first.Configuring Basic Settings of a VLAN InterfaceFor hosts of different VLANs to communicate, you must use a router or Layer 3 switch to perform layer3 forwarding. To achieve this, VLAN interfaces are used.VLAN interfaces are virtual interfaces used for Layer 3 communication between different VLANs. Theydo not exist as physical entities on devices. For each VLAN, you can create one VLAN interface. Youcan assign the VLAN interface an IP address and specify it as the gateway of the VLAN to forward trafficdestined for an IP network segment different from that of the VLAN.Follow these steps to configure basic settings of a VLAN interface:To do… Use the command… RemarksEnter system view system-view —Create a VLANinterface and enterVLAN interface viewinterface vlan-interfacevlan-interface-idRequiredIf the VLAN interface already exists, you enterits view directly.Assign an IP addressto the VLAN interfaceip address ip-address{ mask | mask-length }[ sub ]OptionalNo IP address is assigned to any VLANinterface by default.Configure thedescription of theVLAN interfacedescription textOptionalVLAN interface name is used by default, forexample, Vlan-interface1 Interface.Bring up the VLANinterface undo shutdownOptionalBy default, a VLAN interface is in the up state.In this case, the VLAN interface is up so longas one port in the VLAN is up and goes down ifall ports in the VLAN go down.An administratively shut down VLAN interfacehowever will be in the down state until youbring it up, regardless of how the state of theports in the VLAN changes.
