topic Hi - in Network Security

Cisco ASA 5540 SubInterface VLAN change

stephenkimbro — Tue, 12 Mar 2019 07:35:19 GMT

Our outside interface is a subinterface on our ASA 5540, we are needing to change the vlan on the specific subinterface to change our topology. After testing last night we simply changed the vlan id from ASDM. Waited a few minutes to see if we could ping/route to the outside world. No such luck. My next question after reading multiple posts is: Can we go into the subinterface (config-subif)# and run a "shut" then "no shut" without shutting down the physcial interface itself and all of the said subinterfaces that go with him?

Hi Stephen,

pradypan — Sat, 07 May 2016 01:11:59 GMT

Hi Stephen,

Yes, you can shut/no shut any specific sub-interface on the ASA without shutting down the physical interface.

Shutting/No shutting any specific sub-interface won't impact other sub-interface or the physical interface.

Regards

Pradyumna

Hi -

Paul Chapman — Sun, 08 May 2016 17:23:59 GMT

Hi -

There's one further question that needs to be asked here. Did you permit the new VLAN on the upstream switch(es) and verify the L2 path from end to end? I've changed VLANs on subinterfaces multiple times and never had to restart the interface.

PSC