We are having problems with long idle sessions (2 hrs) between Windows servers and clients that connect to a VIP on CSS. Apparently connection is being dropped on one of firewalls between the load-blananced servers and clients. We tried to enable Windows TCP Keepalives to keep idle connection alive. According to sniffer traces ACKs are not making it thru CSS. Does CSS drop ACKs with seq less than then current one?
Also is there any other solution to send some sort of keepalives on idle connection from the Windows server or CSS VIP towards clients? We dont have control over client systems nor firewalls in the path. Application uses Apache 1.x.
TCP Keep-Alive Messages
A TCP keep-alive packet is simply an ACK with the sequence number set to one less than the current sequence number for the connection. A host receiving one of these ACKs responds with an ACK for the current sequence number. Keep-alives can be used to verify that the computer at the remote end of a connection is still available.