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Layer 5 Load Balancing CSS

Hi, I wonder if anyone can assist me. I have a requirement to load balance at layer 5 from clients to 4 backend servers.

All of the servers have the same content. Clients will use http1.1 and so lots of HTTP GET and PUT commands will be used within a single session. As far as I can see, it should be possible for the CSS to redirect using no persistant every single HTTP request from a single client and spread the load across all 4 servers. This is not happening, all the requests within the session are persisting. The documentation seems to indicate it is possible but I am unable to get this to work.

following is an example of the config I have been using

service SRV1

ip address


service SRV2

ip address


service SRV3

ip address


service SRV4

ip address


content HTTPSRVS

vip address

add service SRV1

add service SRV2

add service SRV3

add service SRV4

no persistent

protocol tcp

port 80

url "/*"


should this do what I am trying to do ?

Also going on from this, is it possible to do the same with TCP sessions so that the CSS becomes the proxy for TCP sessions on different ports not just for HTTP ?


Cisco Employee

Re: Layer 5 Load Balancing CSS

the CSS will break the perisistence only if this is needed. For example, if you do stickyness on a cookie and the cookie changes to a different server, the CSS will then remap the connection to a new server.

In your case, wih no stickyness, the command 'no persistent' is useless.

The behavior that you see is normal.

Remapping the connection takes a lot of resources and is time consuming [you need to make a new 3-way tcp handshake, and close the connection with the previous server].

Moreover, with high number of connections the load will be spread accross all the servers anyway.

If your customer really wants each request to be splitted accross the servers, they should turn off HTTP/1.1 on their servers.


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