DNS on Windows 2000, Second Edition

A Nonrecursive Name Server

By default, resolvers send recursive queries, and name servers do the work required to answer the queries. (If you don’t remember how recursion works, refer to Chapter 2.) In the process of finding the answer to recursive queries, the name servers build up a cache of nonauthoritative information about other zones.

In some circumstances, it is undesirable for name servers to do the extra work required to answer a recursive query or to build up a cache of data. The root name servers are an example of these circumstances. The root name servers are too busy to spend extra effort to recursively find the answer to a request. Instead, they send a response based only on the authoritative data they have. The response may contain the answer, but it is more likely that the response contains a referral to other name servers. And since the root servers do not support recursive queries, they do not build up nonauthoritative data caches, which is good because their caches would be huge.^[37]

You can induce the Microsoft DNS Server to run as a nonrecursive name server by setting the NoRecursion Registry value to true. By default, the name server supports recursion, and this value is false.

If you choose to make one of your servers nonrecursive, do not configure any of your hosts’ resolvers to use it. While you can make your name server nonrecursive, there is no corresponding option to make your resolver work with a nonrecursive name server.^[38]

You can list a nonrecursive ...