Steve,
I will jump in and am sorry that it has been so long.
Mukesh was correct in that you might consider setting up AD Sites. You do
this in Active Directory Sites and Services. Open up this MMC and you will
see what we are talking about. Essentially it is four steps:
1) create the necessary Site(s)
2) create the necessary Subnet(s)
3) associate each subnet with the appropriate Site
4) move the DC(s) to the appropriate Site
You could argue that this is actually a three step process as both #2 and #3
are done when you are creating the Subnet.
By default, when you install the first DC in the forest AD sets up a Site
known as 'Default-First-Site-Name'. You can change this to anything that
makes sense to your environment if you would like. If you have additional
physical locations and making Sites is appropriate then you would have to
create a second Site ( and a third Site and ... ) and give it any name that
makes sense to your environment ( let's call it 'Site2' in this example ).
What you would need to do then is to go into the ADSS MMC, create the
necessary additional Site(s) and then create the appropriate Subnet(s) for
your environment and then associate each subnet to the appropriate Site.
So, if you have two physical locations in your environment and are making
use of, say, the 192.168.1.x 'range' and the 192.168.2.x 'range' you would
have to do the following:
Go into ADSS and create the 192.168.1.0 Subnet and associate it with the
'Default-First-Site-Name'. I would also create the 192.168.2.0 Subnet and
associate it with 'Site2'. Your DC(s) should be located in that
'Default-First-Site-Name' Site already. That is an assumption on my part.
If you have not set up and configured AD Sites then all of your DCs will be
located in the Site named 'Default-First-Site-Name'....I would consider
moving the appropriate DC(s) into 'Site2'. You would do this via the ADSS
MMC.
You have now fully implemented and configured Sites with the appropriate
Subnets in ADSS. Your clients should now find the appropriate DC based on
the Site in which it ( the client ) is located.
I would also consider making at least one of the DCs in each Site a Global
Catalog Server. This may or may not be necessary.
Now, if you have multiple DCs in each Site and you would like clients in
each Site to use a specific DC for purposes of authentication then you could
consider what BrianK suggested -OR- you could simply give the desired DC in
each Site a different priority value ( and, if necessary, a different weight
value ).
HTH,
Cary
