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CSM redundancy

Hello. (Note: I'm not a CSM guru)

I have two 6500s connected to each other via a layer 2 etherchannel trunk. One VLAN is trunked across the etherchannel.

We are thinking of adding a CSM module to each 6500. We are interested in redundancy between the CSMs.

I haven't been able to find any articles or posts on this type of environment. Anybody have any suggestions?


New Member

Re: CSM redundancy

This should work fine, and is done often. Just make sure the client side vlan as well as the server side vlan are included in the trunk.

Servers can be on both switches as well.



Re: CSM redundancy

What if the clients aren't on a VLAN? The ports on the 6500 are IP routed ports. The clients are connected to switches hanging off of these IP routed ports.

Would you just include the server VLAN in the trunk and rely on the intervlan routing to allow the clients to access the servers in the load balanced vlan?


New Member

Re: CSM redundancy

When I say that the client and server vlan need to be in the trunk, I mean the following.

The CSM has vlans configured in the CSM configuration mode. These vlans tell the CSM what L2 vlans it is connected to.

The client vlan is the vlan the CSM receives the connection from. Typically, this is the vlan the CSM used to access its default gateway.

The server vlan is the vlan the CSM uses to send packets to the servers. Typically, this vlan has no MSFC presence (It is strictly a L2 vlan on the Cat6K).

You need to be sure that both of those vlans are included in the trunk. The CSM config should tell you what vlans are the client and server.

If you think your topology needs only one vlan to access the servers and clients, then special configuration is needed to prevent the server response to the client from bypassing the CSM.


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