How maintaining the connection table for sticky/persistent/non-persistent?

[cjrchoi11]

Question about how to maintain the connection table for the source(client) and destination(server) in the CSM(or CSS).

I know the sticky has the table and max size such as 128K(css11501)as per CCO but not clear how works the persistant and non-persistant case.

Q1) persistant. does it maintain the conntion table to tracking the session? then, any information the table size?

Q2) non-persistant. is this also have connection table? then, how it works?

why I'm asking is want to understand how the session keep tracking. for example, the router based on the routing table(stateless) versus PIX firewall has stateful table. As analogue, is the non-persistnet stateless and statefull for the persistent and sticky?

Thnaks in advance,

[Gilles Dufour · Accepted solution]

The CSS uses FCB to maintain information about active connections.

Each connections requires 2 FCB - one for client to vip and one for server to client.

When you boot the CSS it will immediately reserver a good amount of memory to create a list of FCB.

Each connection will then take 2 FCB from the list.

You can do a 'flow stat' from llama mode to verify how much free/used FCB you have.

When running low on FCB, the CSS will try to allocate more memory.

Gilles.