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 GC’s). 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 wasn’t 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 GC’s 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 isn’t. 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 didn’t matter whether the DC/GC was running or not), I couldn’t 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 can’t RDP to the server and I can’t get Windows to recognize a network from the server. And now because there is no network connection, I can’t even open the Exchange Management Shell to undo what I did (because EMS cannot get WinRM to work without a network connection) so EMS can’t 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 night’s backup and hoping that works. I can’t 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