Question : AD site and services best practice

   Hello,
I have 4 DC in a single domain in a single forest. They are all windows 2008 servers. The main one, lets call it PDC, has four subnets in the DHCP scope - 10.0.145.0, 10.0.139.0, 10.0.141.0, 10.0.147.0. The 145 one is where the server resides. The other three subnets are for different properties connected via fiber to the main site. I have a second DC on the 145 subnet in case something happens to the PDC but does not have DHCP role installed. The other two DCs are located in two different properties and connected via T1 lines to the main site. Each one of them distributes their own subnet 10.0.143.0 and 10.0.149.0.

My question is do I have to put them in separate sites in the AD site and services and what should I put under subnets? Right now I have all the servers in one site and I have only the 10.0.145.0, 10.0.149.0 and 10.0.143.0 under the subnets.

Thank you,
Plamen

Answer : AD site and services best practice

To answer your question, you must ask yourself another question.  Would you consider these well connected?  Personally I would consider the properties connected by fiber link to be well connected and thus those subnets would be defined as single site in AD (just my opinion though).  The sites connected by WAN links would individual sites with their subnets and DCs assigned appropriately in "sites and services".

For more information about sites and services please reference

http://technet.microsoft.com/en-us/library/bb727085.aspx