I'm having a communications related issue between a server running Lenel OnGuard and a server running an application called Cameleon. Both servers are running Windows Server 2008 R2. Both servers can ping one another and are able to communicate for the most part. There are no firewalls enabled, the systems reside on a closed loop.
To give a little background our Lenel server receives events (card swipes, intrusion alarms etc...) and sends them to Cameleon as an alarm or event. The problem I'm having is the two seem to lose connectivity and the events are no longer sent from Lenel to Cameleon. A reboot of Cameleon will bring back functionality, albeit briefly. For example if I come in at 8 in the morning and reboot Cameleon it will receive events for maybe 30 minutes. If I restart it after it stops in the morning I'll then receive events for maybe 5-10 minutes. If I reboot again it might stay up for 2 minutes. If I leave it down for a few hours and reboot it will usually run again for about 30 minutes. So the length at which it's down effects the time it will stay up upon reboot. Another interesting thing is even when the communication is down I can send a command from Cameleon to Lenel and the command will carry out. So there is always some communication.
For over a year all has been running well until recently. One of our on-site technicians installed a few Windows updates at which point this problem started occurring. The updates have been removed however the issue persists. The only error that we've found is from Cameleon. The error reads as "Connection Error : m_WMIServices.ExecNotificationQueryAsync(lnl_securityevent) - The RPC service is Unavailable." We've checked the services, we have everything enabled that should be, event logs don't point to anything going down during these times. I really don't know a lot about WMI. Frankly the most frustrating part is that it will work at times. If it didn't work at all I feel like it would be easier to troubleshoot.
Any ideas would be appreciated.