Vlan Interface internal loopback command

[austin.davis]

Hi all,

What does this loopback command do in the following config? There is not any documentation on it that i could find:

TEST-C3560CX#
TEST-C3560CX#conf t
Enter configuration commands, one per line. End with CNTL/Z.
TEST-C3560CX(config)#int vlan 3
TEST-C3560CX(config-if)#loo
TEST-C3560CX(config-if)#loopback
Loopback is a traffic-affecting operation
IPv6 self ping is not supported
TEST-C3560CX(config-if)

My thoughts were that it created a soft loop within the vlan for testing. I created the vlan 3 interface, entered the loop back command, and made an access port on vlan 3. I plugged a T-berd into the access port to do a loopback test and my t-berd doesnt see the loopback. Is my train of thought wrong or did i just do something wrong? There is no documentation on this command other than the description which suggests the same as what im thinking:

TEST-C3560CX(config)#int vlan 3

TEST-C3560CX(config-if)#?
Interface configuration commands:

loopback          Configure internal loopback on an interface

Thanks

[Richard Burts · Accepted solution]

Where I have seen this used is on physical interfaces. I am not sure that it works on virtual interfaces like vlan interfaces.

HTH

Rick

[austin.davis]

Hi Richard,

This is on a  WS-C3560CX-8TC-S running  c3560cx-universalk9-mz.152-4.E2

The command doesn't exist as an option on a physical port but i can use it in a virtual one. Maybe they forgot to delete this command lol