we are running exchange 2010 SP2 rollup 6 and hardware load balancer from F5.
we have 1 site which contains 4 exchagnge servers and each is HUB+CAS+MBX. F5 running as load balancer/CAS array which distribute the connections to CAS servers in round robin fashion.
Yesterday, we have an issue where multiple users (not all) start reporting that their outlook keep stuck on "trying to connect" we have check all 4 CAS server and 1 server was not having any active connection with it, we asked our network team to remove that server from load balancing pool and immediately after that everythign start working.
That CAS server was containing few databases which was working mounted and healthy during that time.
After 24 hours of smooth operation we again put that server in POOL and same thing start happening.
Need your expert comments and advice on this.
NOTE: I have'nt explained EDGE as i think its not related to this issue.