Any issue if we remove the unued VLAN from CSM

Unanswered Question
Mar 26th, 2009
User Badges:

We found we had a mis-configuration on our CSM. We added a unused VLAN on CSM. like :

vlan 72 server

ip address alt


If I tired to "sh mod con 5 arp", I found CSM learned the mac-address of whole VLAN 72.I also found some connections with other servers including in CSM from vlan 72 when I used "sh mod con 5 conn". I checked the settings of vlan 72 servers and the GW of servers is not pointed to CSM.So My question is any issue happened if we remove the vlan72 from CSM. Does it cause vlan 72 flipping?

please give me a hand. Thanks!!!

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Gilles Dufour Thu, 03/26/2009 - 09:34
User Badges:
  • Cisco Employee,

See the CSM as an external gateway.

If you remove vlan 72 from the CSM it is just live unplugging the cable that connects the CSM to the cat6k.

It should not affect the cat6k or the other devices in vlan 72.


HWangLoyalty_2 Thu, 03/26/2009 - 10:45
User Badges:


But Would the connection be lost between vlan 72 and other vlans located on CSM when we remove vlan72 on CSM?

please advice!!

Gilles Dufour Fri, 03/27/2009 - 01:49
User Badges:
  • Cisco Employee,

if you have no route from vlan72 to the CSM, yes you won't be able to access the CSM vlans.

Check the routing table from your host to the CSM (check every hop in-between).

Removing the vlan will also kill all active connections that uses vlan72.

Clients will have to open a new connection.



This Discussion