I’m in the process of going through Exchange configuration in an environment that I just took over. Autodiscover is next. I’ve been told that we need to keep at least 1 2003 dc in the mix so for autodiscover to work correctly. I think this statement is meant to be an environmental one, specific to how we’re setup. I noticed that when I connect using http/rpc, I got a password prompt and the computer I was authenticating with is a 2003 dc. So, my first question is – Is there a setting to look to a specific DC for authentication with autodiscover?

You need a DC iregardless of autodiscover or not. For the domain joined comuter, it will contact a DC, find the service connection point (SCP) in AD which will return the list of CAS servers to connect to. For clients connecting over outlook anywhere, they will be using DNS or srv method to resolve to your CAS serversto locate the autodiscover service. For example https://<smtp-address-domain>/autodiscover/autodiscover.xml or https://autodiscover.<smtp-address-domain>/autodiscover/autodiscover.xml, where ://<smtp-address-domain> is the primary SMTP domain address.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

It is the specific dc that I'm questioning. Is there a configuration setting that sets a specific dc to be queried?

Whoever told you that about the domain controller was incorrect. I would ask them to provide documentation to that fact. There is no version dependency on version of the domain controller for autodiscover. There is no specific server dependency either. That would be rather dumb on Microsoft's part if you had to keep an old unsupported version of Windows in use. The only way that I can think that someone came up with this ludicrous thought is that when that DC was removed - things stopped working as they should. That may well be the case because Exchange will attach itself to a specific domain controller and doesn't look for another one immediately. It could also have been something to do with the way that autodiscover queries certain URLs for non-domain members, one of which being example.com (where example.com is the domain after the @ sign). In AD domain called "example.com" the host "example.com" will resolve to a domain controller. However in a correctly functioning network this isn't a problem. If you want rid of that DC, then take away the GC role and immediately restart the System Attendant role on the Exchange servers. That will force Exchange to look for another GC/DC. Then you can run DCPROMO to remove it. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

I imagine you're exactly right on why it was determined that a 2003 dc is required - after it was removed there were issues. I want to be sure there isn't something configured to specifically point to this dc so I don't "break email". Thanks for the information!!