Enabling Service Loopback of VLAN

A loopback interface is a virtual interface that is always up and reachable as long as at least one of the IP interfaces on the switch is operational. As a result, a loopback interface is useful for debugging tasks since its IP address can always be pinged if any other switch interface is up.

1. To configure a VLAN in loopback mode, use the vlan loopback enable command in VLAN Configuration Mode.
   perform the following:

   iS5comm# configure terminal

   iS5comm(config)# vlan 2

   iS5comm (config-vlan)# vlan active

   iS5comm(config-vlan)# end

2. View the service loopback status of a VLAN by executing the following command.
   perform the following:

   iS5comm# show vlan id 2

   VLAN database

   -------------

   VLAN ID             : 2

   Member Ports        : Gi0/2, Gi0/3, Gi0/4, Gi0/5

   Untagged Ports      : None

   Forbidden Ports     : Gi0/1

   Name                :

   Status              : Permanent

   Egress Ethertype    : 0x8100

   Service Loopback Status   : Enabled