Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

CSS Redundancy

I hope I myself am not acting redundant, since I see some similar threads on the forum. Bear with me as I ask yet again:

What is the best form of CSS 11503 redundancy?

Ideally I'd like to do ASR. And I assume that in a redundant load balancer configuration, instead of direct attaching my servers to the CSS, I would put all servers into an intervening switch, and the two CSSes also into the same switch - so I didn't have to deal with dual attached servers as well. Is that the standard design for this setup?

The first load balancer is running version, Standard Feature Set. Do I have to get an upgraded feature set for the redundant configuration? Do I need to upgrade to do ASR?

And finally - both CSSes have the 16 port interface cards. Is there anyway for me to still leverage my investment in those modules - ie does anyone do a dual load balancer configuration where the servers themselves are dual-attached to both load balancers?

I really hope all that rambling made some sense.

Thank you!



Re: CSS Redundancy

Yes, the ASR configuration should work. This will be the best way and the most efficient way to achieve CSS redundancy.

New Member

Re: CSS Redundancy


you can look my post titled " CSS, PIX, Layer2 Switch".

I am also using ASR mode redundancy and I posted sample config too. May it would be helpful to you.

nayan Panchal

Cisco Employee

Re: CSS Redundancy


I would avoid the dual-attachment of the PC.

I have only seen issues with this solution. If somebody is using successfully such a setup, please let us know.

ASR does not require an extended license. It comes with the basic one.

Having another module inside the CSS even if not used to connect to other devices is very useful.

The CSS has a distributed architecture, so the traffic is splitted over all the modules [even the ones not being used].

So your unused module is giving you more performance.

If you go in llama mode and execute a 'flow stats' you should see the resources being used on that module.