Abstract: I need to create site(s) in my existing Active Directory to assist with the implementation of DFS.
Environment: Windows 2003 Forest, single domain, two physical sites connected with a 6Mbps link; only one logical site in active directory. At least one DC exists at each physical site. No subnets are defined in the Default-First-Site. All DCs are GCs and the other FSMO roles are held by a DC (DCa) at the main site (Site A).
Problem: I created a new Site in AD to represent my second physical site (Site B). I then created the proper subnet and site link. I then moved the DC already present at the physical site (DCb) into Site B. After a few minutes several of my member servers at Site A became "unavailable". That is they simply lost network connectivity -- I could not ping to them but I could initiate pings from them. After moving DCb back to Site A and deleting Site B (and its subnet and removing it from the site link) things started to return to normal.
Question: I have two questions, the first is less important. 1. What could have caused this; and 2. What do I need to do differently when I try this again?
I realize this is somewhat complex and will be around to clarify anything. Thanks in advance!