Hi

We have 2 DC, 1 for every site, the replication has been modified to occur every hour for bandwith limitations, the Exchange environment has 4 servers, 2 CAS 2 MailBox in DAG.

We had to define an static DC and GC and ConfigurationDC statically in every Exchange server (the DC in the same Exchange's site), because we note that for an strange reason, the Exchange servers use the other DC out of the site.

The point is: If the only DC that We defined statically could fail, How can we change the 4 Exchange servers to use the other DC out of the site to mantain working the Mail System?

We made some tests and when I disconnect the DC in the same Exchange's site, and I try to open the EMS to run Set-ExchangeServer, never appear the prompt to put the command.

I tried in another server where the EMS was already opened, I ran the Set-ExchangeServer cmdlet and also never accept the comando.

The 4 Exchange servers have both DCs in their DNS of their NICs.

Is there a way to switch the 4 servers to use the remaining DC? may be by registry or some thing else like ASDIEdit....

Or

Is there a way to define a strict order of use of the domain controllers?, because even if I define both DC in order by Set-ExchangeServer, they take any of the DC, so this is the reason of this question.

Thans in adv

This is why the practice of assigning static DCs is discouraged.  If you want to select certain DCs to be used by Exchange, consider configuring a separate AD site for the Exchange servers and the DCs it should be using.

Yes Ed, that's correct, we most avoid assigning DCs statically, but in some situations it's neccesary... So I found a workaround:

http://www.c7solutions.com/2012/05/starting-exchange-when-you-have-active-html

Not neccesary create the "MinUserDC" in profiles (only for Exchange 2013)