Microsoft KB Archive/290522

= The Domain Name Resolver Local Network Priority Sorting Does Not Work in Some Configurations =

Article ID: 290522

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Workstation 4.0 Developer Edition
 * Microsoft Windows NT Server 4.0 Standard Edition
 * Microsoft Windows NT Server 4.0 Enterprise Edition

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This article was previously published under Q290522



SUMMARY
This article discusses the Domain Name Resolver (DNR) and how it does not perform local network priority sorting with some network configurations.



MORE INFORMATION
This behavior can only occur if you have the following configurations:
 * You have a multihomed Domain Name System (DNS) client computer that has more than 10 network interfaces configured.
 * Dynamic Host Configuration Protocol (DHCP) is enabled on at least one of these network interfaces.
 * You use a remote DNS server (located in a separate Internet Protocol [IP] segment).
 * You use a multihomed remote DNS client.

DNR does not sort the list of IP addresses (returned by the DNS server) to select an address on the local subnet. Instead, DNR selects the first address on the list (the type of behavior DNR had before Windows NT 4.0 Service Pack 4 [SP4]).

DNR in Windows NT 4.0 SP4 or later, sorts the list of IP addresses that it receives from the DNS server for a multihomed host into the &quot;best&quot; order by examining the route table of the computer on which it runs. For example, if any of the IP addresses in the list (returned by the DNR) are on a common subnet with the client, that IP address is moved to the top of the list.

For additional information about this feature, click the article number below to view the article in the Microsoft Knowledge Base:

182644 DNR Now Sorts IP Addresses for a multihomed Host Before Returning the List to Winsock Applications

If you change all network interfaces to static IP addresses or reduce the number of network interfaces to eight or less, your computer does not have the preceding behavior.

