I have started to get an issue with my IronPort WSAs where they are automatically clearing their authcache on their own very frequently. So frequent that I have users that are on sitest for a short time but then get kicked out saying that they are no longer authenticated. The block page gives them the opportunity to re-authenticate to LDAP at which point they continue to work until they are kicked out again. What could cause this and how can I fix it?
Also double check what is the surrogate timeout that you have set, you can check this from GUI -> Network -> authentication -> Credential Cache Options -> check the Surrogate Timeout.
