Posted on 2013-01-20
I have a new Exchange 2010 Server which is having strange problems. Some users (but not all) from time to time are being disconnected or outlook hangs and has to be forced to close before it will work. I checked exchange and I found the following error messages:
1) The Security System could not establish a secured connection with the server ldap/domain. No authentication protocol was available.
2) Process MAD.exe (PID=4476). Exchange Active Directory Provider lost contact with domain controller dc.domain.com. Error was 0x80040951(LDAP_SERVER_DOWN (Cannot contact the LDAP server)) 0. Exchange Active Directory Provider will attempt to reconnect with this domain controller when it is reachable.
3) Proces MSExchangeMailboxAssistants.exe (PID=2624). Exchange Active Directory Provider lost contact with DC.domain.com. Error was 0x34 (Unavailable) (Active Directory response: The server is unavailable). Exchange Active Directory Provider will attempt to reconnect with this domain controller when it is reachable.
Once this machine is restarted, it works fine for another few hours, then it starts playing up again. I am in the middle of removing two Windows 2003 DCs but the Exchange (which is virtual hyper v server) is currently pointing to our Windows 2008 DC.