We have 2 Windows 2003 DC's running Active Directory on a Domain. I'll call them Server A and Server B. Server A provides our DNS and file and print services while Server B provides Anti-Virus and other misc services.
We are having a sporadic problem with what appears to be a DNS issue. Some of the workstations will (while the user is working) lose it's connection to Server B. The Anti-Virus application icon in the system tray suddenly has a red "X" on it which notifies that it is no longer seeing Server B. The user can no longer access any resource on that server.
When I go over and check things out, this is what I get:
Pinging the IP address of that server works fine
Pinging the name of that server times out b/c it can't resolve the host name.
These are the things that have fixed the problem
Adding a entry in the hosts file on the workstation
Clearing the DNS resolver cache on the workstation and then cold booting it
Letting the machine sit for quite some time (some refresh of DNS records?)
note: Server A (the DNS server) does have an "A record" in the forward lookup zone with the proper name and IP for Server B.
Any thoughts on what would cause the workstation to lose an already established connection to Server B and then not being able to resolve the name, but then it can later?