We are running Windows 2003 server in a single domain config, 2 DC's both running DNS. 9 subnets. Lately, just lately, people are occasionally unable to access resources to a file server in xxx.xxx.xxx.1 by name, but they can do so by IP address. Mapping a drive to \\xxx.xxx.xxx.x\share works where using the name of the server does not. Further, occasionally a person will lose connectivity to the Exchange 2003 server (same subnet as the file server), Pinging the exchange server by name from that client returns the outside address of the exchange server instead of the inside address. A \flushdns on the client fixes the problem right away. None of the clients are in the same subnet as the server. All of the servers are in the same subnet, but only 2 of the servers seem to have problems. People are able to log on and get to the internet with no problems. This happens in several subnets. DCDIAG and NETDIAG test both pass, except for the root hint errors which can safely be ignored (???? - really?). Should any external name servers (ISP) be included in the list of the reverse lookup zones? How exactly should the subnetted zones be configured? Any thoughts on where to look to find the cause of this would be appreciated.