I have Exchange 2013 (minimal install and all roles are on a single server) on-premises running on a Windows 2012 R2 server (both Windows and Exchange are patched and up-to-date).  Basically this system serves as our on-premises hybrid for Office 365 stuff and on-premises SMTP.  This server is a VM.

Our AD is at 2008 R2 level and we have a few DC (all of them are GCs).  I am trying to remove a DC from the network but when I shut the DC down, my Exchange server has issues.  When I removed the GC from the DC and turned the DC server off, I rebooted my Exchange 2013 VM and I wasnt able to RDP to it.  Luckily it is a VM and I could log on to it using VM tools.  When the DC is powered down, I look at the network on the Exchange server and I see that there are no networks available within Windows (location awareness issue maybe?).  If I power the DC back up and make it a GC again, the Exchange server works fine (there are other GCs on the network and associated with this site in AD).  I would think that Exchange 2013 should detect that the DC is offline and it should choose another GC but it isnt.  So I tried to exclude the DC that I want to shut down in Exchange (by using the Set-ExchangeServer cmdlet with the StaticExcludedDomainControllers parameter) and that broke the server completely.  Once I did that and tried to reboot the Exchange server (it didnt matter whether the DC/GC was running or not), I couldnt get Exchange working again.  Now there is nothing available in the network connections on the Windows 2012 R2 server side (I guess that is why Exchange services are failing).  However, I can ping the server, I can browse network file shares from the server, and other network stuff all from the Windows 2012 R2 server, I just cant RDP to the server and I cant get Windows to recognize a network from the server.  And now because there is no network connection, I cant even open the Exchange Management Shell to undo what I did (because EMS cannot get WinRM to work without a network connection) so EMS cant communicate with the Exchange server and therefore it fails.  When the EMS was working, the Get-ExchangeServer cmdlet showed the DC as the OriginatingServer also.

I am now in the process of performing a restore from last nights backup and hoping that works.  I cant figure out why turning off the DC / GC would cause Windows 2012 R2 to lose the network connection and/or cause Exchange 2013 to not work?  And why would Set-ExchangeServer cause this same issue?  Is there any known reason for this occurring?  What is the proper method to remove a DC/GC from an Exchange 2013 environment?

Thanks

I should think that you not being able to RDP into the server would tell you that the problem is a Windows AD connectivity problem of some sort and not an Exchange problem.

I recommend that you post this in the Active Directory Services Forum: http://social.technet.microsoft.com/Forums/en-US/winserverDS/threads