Here's the gist. Have an old DC (2003 R2), which was getting long in the tooth. So I created a new DC (2003 R2) through DCPROMO, AD integrated, DNS intergrated, and transfered all five fsmo rolls to it. Additionally I made it the DHCP server.
We have exchange 2003. When both the old and new DC's are up the netdiags and dcdiags are all passing. However if the old DC dies (mostly after a MS security update , users lose access to exchange, shared drives, etc, as well as the ability to logon.
Any suggestions would be appreciated.