Problem Definition:
When using SSO, several machines work one day, but are timing out the next.
Resolution or Workaround:
First, make certain the SSO agent is installed on a machine that is NOT the Domain Controller. This has been known to cause issues with user recognition.
If the problem persists, set the SSO agent logging level to debug, and check the SSO logs to determine if it is getting errors querying those machines. Check for any errors encountered for those IPs in the Knowledge base.
Finally, make certain the SSO agent is not losing communication with the firewall. A packet capture can be run on port 2258 (by default) to monitor SSO communication between the SonicWall appliance and the SSO agent.