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 After associating an isolate-user-VLAN with a secondary VLAN, you cannot add ports to, removeports from, or remove, the VLANs. To do that, remove the association first.z A VLAN operating as a probe VLAN for remote port mirroring or an RRPP protected VLAN cannotbe removed with the undo vlan command. To do that, remove the remote mirroring VLAN orRRPP protected 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 VLAN interface andenter VLAN interface viewinterface vlan-interfacevlan-interface-idRequiredIf the VLAN interface already exists,you enter its view directly.Assign an IP address to theVLAN interfaceip address ip-address{ mask | mask-length } [ sub ]OptionalNo IP address is assigned to anyVLAN interface by default.Configure the description ofthe VLAN interface description textOptionalVLAN interface name is used bydefault, for example,Vlan-interface1 Interface.Bring up the VLAN interface undo shutdownOptionalBy default, a VLAN interface is in theup state. In this case, the VLANinterface is up so long as one port inthe VLAN is up and goes down if allports in the VLAN go down.An administratively shut down VLANinterface however will be in the downstate until you bring it up, regardlessof how the state of the ports in theVLAN changes.
