DNS Caches Last Negative Response Returned on Multihomed Server

When you query a Domain Name Service (DNS) name from a multihomed Windows 2000-based computer that is connected to disjoint networks, you may receive a negative name response for an existing name. For example, if you query record type TXT for dns.bar.com and the name does not exist, you receive a negative name response. If you then query for an existing A record for eg.dns.bar.com, the name query is unsuccessful.

This behavior can occur if your multihomed computer is running Microsoft Proxy Server, which can incorrectly cache the negative name response under the following situations:

• The first adapter on your multihomed computer returns a NAME_ERROR response (name does not exist) for the queried name, and DNS times out before you receive a response from the second adapter. In this situation, your computer incorrectly caches the NAME_ERROR response.
• The first adapter returns a NO_RECORDS response (name exists, but not for this record type), and the second adapter returns a NAME_ERROR response (name does not exist). In this situation, the last response is cached, and queries for any record type for this name do not work.

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

This problem was first corrected in Windows 2000 Service Pack 1.

When a NAME_ERROR response for a name is cached, additional queries for the cached name do not work even if the record type being queried exists. This behavior occurs because the name query is never sent over the network, and the cached response is returned.

For additional information about how to install Windows 2000 and Windows 2000 hotfixes at the same time, click the article number below to view the article in the Microsoft Knowledge Base: