CSM bridge mode and gateway command

Unanswered Question
Dec 2nd, 2007


We are using the CSM blade in bridge mode (or daring to do so).

We had a problem with the blade some time ago, the blade stopping to forward traffic from the client vlan to the server vlan without any error...

This w-e we had the same problem and adding the gateway command on the client or server vlan seemed to solve the issue.

However, I thought that the gateway command (like the alias command ) was used only in routed mode.

Anyone can explain the exact role of the gateway command in bridge mode ?


I have this problem too.
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Gilles Dufour Mon, 12/03/2007 - 04:32

if you have L7 rules - ie: header map or sticky cookie, ... - then the CSM needs to terminate the connection and to respond to the client it requires a valid route.

Another reason is that the CSM does a reverse-path lookup to make sure the client comes in on the correct vlan.


csco10387876 Mon, 12/03/2007 - 05:02

Hi Gilles,

This is really strange, this was the same problem we looked at some month ago.

What is strant is that it works for some "DMZ" without the gateway command.

Here with the gateway comand on either side it seemed to work.

I tried to check on each processor if I could find errors without success.

I tried the gateway command without real hope but I think that the Reverse path check must be the cause indeed.

The documentation of the CSM is really bad I think.


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