How to Prevent a DNS Server from Caching Records from Recursive Queries

ID: Q245469

The information in this article applies to:
  • Microsoft Windows NT Server versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a
  • Microsoft Windows NT Server, Enterprise Edition versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a
  • Microsoft Windows NT Server versions 4.0 SP4, 4.0 SP5, Terminal Server Edition
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

As a Domain Name System (DNS) server performs name resolution for a name query, it caches a copy of the data. This is retained for the time period specified by the Time To Live (TTL) value. By default, the data is kept in memory until the TTL time period has expired, DNS has been stopped, or the MaxCacheTtl value on the DNS server has expired, whichever occurs first.


MORE INFORMATION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

To prevent a Microsoft DNS server from caching records from recursive queries:

  1. Start Registry Editor (Regedt32.exe).


  2. Locate the following registry key:


    3. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Parameters
  3. On the Edit menu, click Add Value, and then add the following value:


    4. Value: MaxCacheTtl
    Data Type: DWORD
    Data value: 0
  4. Click OK.


  5. Quit Registry Editor.


  6. Restart the DNS server.


For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
Q198408 Microsoft DNS Server Registry Parameters, Part 1 of 3

Additional query words:

Keywords : kbenv
Version : winnt:4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Platform : winnt
Issue type : kbinfo


Last Reviewed: December 22, 1999
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