DNS on Windows Server 2003, 3rd Edition

Multiple Servers

nslookup talks to only one name server at a time. This is the major difference between nslookup’s behavior and the resolver’s behavior. The resolver makes use of all the name servers listed in the Windows resolver configuration window. If two name servers are listed, the resolver tries the first name server, then the second, then the first, then the second, until it receives a response or gives up. The resolver does this for every query. On the other hand, nslookup tries only the first name server listed. But you want your troubleshooting tool to talk with only one name server so you can reduce the number of variables when analyzing a problem. If nslookup used more than one name server, you wouldn’t have as much control over your troubleshooting session.