cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

133
Views
0
Helpful
3
Replies
Enthusiast

CSM Trunk

I have been told that a CSM by default has all VLANs on the Cat 6500 trunked on its connection to the backplane and the catalyst autostate feature does not work in this case as you cannot remove the VLAN from the trunk. To explain it a little better ... if all the ports on a VLAN go down the Catalyst does not declare the corresponding layer 3 interface as down because the trunk to CSM is still carrying this VLAN even though it is not required to go to the CSM. Unfortunately i do not have a CSM module handy to test this so will appreciate if someone can shed some light on this issue as i think it is pretty unlikely that this happens in reality otherwise having a CSM can cause a lot of issues especially if one uses the autostate feature for some unorthodox routing.

3 REPLIES 3
Cisco Employee

Re: CSM Trunk

This is true autostate does not work with the CSM.

It is also true that with Native you do not control the vlan on the trunk to the CSM.

However with hybrid you do control the list of vlan to the CSM.

One simple reason for autostate not to work with the csm is that you can use the csm in bridge mode.

A vlan is used only between MSFC and CSM.

Regards,

Gilles.

Highlighted
Enthusiast

Re: CSM Trunk

Gilles, thanks for the reply. One last clarification. In Native mode autostate will not work for all VLANs whether they are being used on the CSM or not? In hybrid mode the autostate for a VLAN will work as long as i do not trunk that VLAN to the CSM?

Cisco Employee

Re: CSM Trunk

correct.

CreatePlease to create content
Content for Community-Ad
August's Community Spotlight Awards