Windows Server 2008 R2 with SP1. IP address statically assigned is 192.168.10.12. Roles are Active Directory Services, AD Certificates, DHCP, DNS, File Services (DFS), and Print services.
This server replaced another server last night with the same services, but IP was 192.168.10.11.
PCs are running Windows 7 x64 (with and without SP1). We have about 100 PCs. All but 4 are working with the new server just fine. These 4 will get DHCP information from the server. They'll get an IP (which gets put into the DHCP reservation list). They'll get subnet mask, gateway, and DNS server information just fine. Their dynamic network properties are populated just fine. These 4 machines can ping the email server, the vpn server, and any IP address on the network except for the Windows server (192.168.10.12). It just times out.
If I put in the same IP / network information into the PCs statically, they work just fine. Only when getting the information via DHCP do they fail.
I tried fixing them by doing
sfc /scannow
netsh winsock reset
netsh int ip reset
Even removed the NIC from device manager and had it reinstall it. I've even removed the PC from the Domain and rejoined it to reset that information. I removed all references to the PCs from the DHCP and DNS servers.
Doing all of that, 1 of the PCs now works fine. The others do not though. I've tried various sequences of the above steps. I've done reboots after each step. I've tried everything I can think of. Can anyone offer me any clues?