How Internet Explorer uses the cache for DNS host entries (263558)


The information in this article applies to:

  • Microsoft Internet Explorer 5.5 for Windows 98
  • Microsoft Internet Explorer 5.01 for Windows 98 SP 1
  • Microsoft Internet Explorer 5.0 for Windows 98
  • Microsoft Internet Explorer 4.01 for Windows 98 SP 2
  • Microsoft Internet Explorer 5.5 for Windows 95
  • Microsoft Internet Explorer 5.01 for Windows 95 SP 1
  • Microsoft Internet Explorer 5.0 for Windows 95
  • Microsoft Internet Explorer 4.01 for Windows 95 SP 1
  • Microsoft Internet Explorer 4.01 for Windows 95 SP 2
  • Microsoft Internet Explorer 4.0 for Windows 95
  • Microsoft Internet Explorer 5.5 for Windows 2000
  • Microsoft Internet Explorer 5.01 for Windows 2000 SP 1
  • Microsoft Internet Explorer version 6 for Windows 2000
  • Microsoft Internet Explorer version 6 for Windows 98
  • Microsoft Internet Explorer version 6 for Windows 98 Second Edition
  • Microsoft Internet Explorer version 6 for Windows Millennium Edition
  • Microsoft Internet Explorer version 6 for Windows NT 4.0
This article was previously published under Q263558
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

SUMMARY

In earlier versions of Internet Explorer (Internet Explorer 3.x), DNS host entries are cached for 24 hours by default. In many cases, this is too long. During this period, some host entries stop working because of change in the IP address of the remote server that was initially resolved.

Internet Explorer 4.x and later versions modify how DNS host entries are cached by decreasing the default time-out value to 30 minutes.

MORE INFORMATION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

In some cases, this new time-out setting is too short. If your environment has a number of clients that are connecting and are all performing DNS lookups every 30 minutes, you may experience an unwanted increase in network traffic. To modify this behavior, make the following registry change:
  1. Start Registry Editor.
  2. Locate and click the following key in the registry:

    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings

  3. On the Edit menu, click Add Value, and then add the following registry values:

    Value Name: DnsCacheTimeout
    Data Type: REG_DWORD
    Radix: Decimal
    Value: (time in seconds)

    Value Name: ServerInfoTimeOut
    Data Type: REG_DWORD
    Radix: Decimal
    Value: (time in seconds)

  4. Quit Registry Editor.
For example, to set the time-out value to 10 minutes, use a value of 600 seconds.
Note You must use both the registry values listed in step 3 to control the Internet Explorer internal resolver cache mechanism.
Modification Type:MajorLast Reviewed:11/25/2004
Keywords:kbhowto kbenv kbinfo KB263558
©2004 Microsoft Corporation. All rights reserved.