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I'm looking to setup Active directory for my workplace. We have a main office in Ohio and two remote offices in Texas and California. My goal is to have a domain controller at each office, we already have the necessary VPN connections in place to connect the remote offices back to the main office in Ohio.

Currently we have the following domain structure in place: The main office DNS server suffix is and the remote locations are and

I'd like to have an active directory domain setup for each of these all under the forest. I understand how to setup the remote locations by simply selecting create a new child in existing forest when setting up the domain controller. My confusion comes when setting up the domain controller at the main Ohio office. From what I can tell you can only run a single domain on each Windows Server. I really don't want to have to run a server to host the forest and another to host I'm assuming there is a better way to set this up.

My alternative would be to put all the offices in the same domain,, but I'd rather have them in their own domains. I'd appreciate any thoughts and suggestions on how to setup this configuration.

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Is an actual site on the Internet already? If so, you're going to want to avoid using it as an AD forest/domain name as well. – MDMarra May 1 '12 at 1:26
The domain name is used strictly for local network use, it is not an internet domain. – Jared May 1 '12 at 1:35
Do you already have a forest called or is your forest – Mark Henderson May 1 '12 at 2:49
There currently are no active directory domains. currently exists solely for dns use. The windows 2008 servers would be new installs. – Jared May 1 '12 at 2:53

You are correct in stating that can only have one domain per domain controller. This is where the higher versions of Windows Servers' virtualisation rights come in handy.

For example, we have a few sites as well. We have a local domain controller in each site, and in the main site, we have two domain controllers for each domain. So I actually have six domain controllers in the central office. Two of them are for our primary domain that we work work off, and then there are two for each other domain.

To do this legitimately, we licensed two CPUs of Windows Server Datacenter Edition. Once you pass a certain threshold, it's cheaper to just go a license that permits you unlimited virtual instances*. Because the domain controllers themselves do not have to be powerful machines, you can easilly fit 4 or 6 of them onto an entry level virtualisation server (for example, all of the DC's in this office fit inside 4 cores and 8gb of RAM). Microsoft provide a great calculator** for figuring out where your thresholds are.

There are plenty of free hypervisors to choose from. Any purchase of a Windows Server license gives you an additional license to use strictly as a hypervisor; or there's the free Hyper-V server if you wish. Or, there's the free tier or VMWare ESXi. Both ESXi and Hyper-V have cheap tiers if you want to go further than their basic editions allow.

* This does NOT constitute licensing advice. There are caveats to the usage of the virtual machines. Speak to your MS licensing specialist before committing to anything based on what I've said.

** We have four dual-socket servers in this office that have about 20 VM's on each server. It was less than half the price to license Datacenter edition, and it's much much easier to keep track of your entitlements.

share|improve this answer
I'm trying to keep server cost to a minimum, thus the fewer licences I need to purchase the better. I'm beginning to think that a single domain in the forest would be the most cost effective as it would eliminate the need for another license. If I went this route would I still be able to setup the DNS server/subnets so that the offices would resolve on, and yet have them all be a part of a domain? – Jared May 2 '12 at 19:58

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