Have seen this question asked elsewhere but no real answer. In our scenario:
Active Directory Site A (Colocation)
192.168.1.0/24
DFS Server #1: 192.168.1.10 (Server 2003 R2 SP2)
DFS Server #2: 192.168.1.12 (Server 2008 R2 SP1)
-- Colocation facility, no clients present
Active Directory Site B (Branch)
192.168.5.0/24
DFS Server #3: 192.168.5.10 (Server 2008 R2 SP1)
DFS Server #4: 192.168.5.12 (Server 2008 R2 SP1)
Clients in: 192.168.5.100 to .199
Active Directory Site C (Branch)
192.168.7.0/24
DFS Server #5: 192.168.7.10 (Server 2008 R2 SP1)
DFS Server #6: 192.168.7.12 (Server 2008 R2 SP1)
Clients in: 192.168.7.100 to .199
NOTES:
1.) All 3 sites, and their IP subnets, are defined in Active Directory.
2.) DFS Management console lists each DFS server as being in the correct site.
3.) All sites have 2 DFS servers for high availability per site (to avoid off-site DFS referrals during reboots).
4.) All sites are interconnected by static site-to-site VPNs over 50 Mbps WAN link.
5.) All clients are Windows 7 Professional.
Example problem: Some clients in Site C get random DFS referrals to servers in Site A and Site B, even though both DFS servers at Site C are online and available.
Why would clients get DFS referrals to servers off-site, when there is ALWAYS anon-site DFS server available?