We have one 2003 Domain Controller and a Server 2008 R2 Exchange 2010 Server. The Exchange System Attendant service will not start. When I open up Active Directory Users & Computers on the Exchange Server (not a DC) - go to Domain Controllers, select properties of the DC and select the "Member of" tab - it tells me that the GC is not available. I added a 2nd DC - this time a 2008 R2 Server and GC. When this Server is on, the Exchange Server can find the GC and the Exchange System Attendant service can start. When this Server is off - it can't. The GC seems to replicate fine from the 2003 Server to the 2008. How do I troubleshoot the 2003 Global Catalog problem?

So both your DCs (2003 and 2008) are also GCs? If that's the case, check to see whether the original DC has been explicitly excluded: http://support.microsoft.com/kb/298879Tony www.activedir.org blog:www.open-a-socket.com

In addition to Tony you may also try posting this in the exchange server forums http://social.technet.microsoft.com/Forums/en-US/exchangesvrgeneral/threads http://www.arabitpro.com

So both your DCs (2003 and 2008) are also GCs? If that's the case, check to see whether the original DC has been explicitly excluded: http://support.microsoft.com/kb/298879 I checked and there are no excluded DCs. We don't want to keep the 2008 R2 DC (for now). We want the 2003 DC Global Catalog working correctly with Exchange 2010.

Look for event 2080 (MSExchange ADAccess) in your application event logs. This should indicate why the Exchange server has decided to ignore your 2003 DC/GC. The characteristics can be interpreted using this kb article: http://support.microsoft.com/kb/316300 I suspect it might be SACL rights.Tony www.activedir.org blog:www.open-a-socket.com

I ended up calling Microsoft on this issue and we found that the 2003 Server was not set to register it's connection's address in DNS. As soon as we turned this on, everything worked correctly.