Windows IT Pro is the authoritative and independent resource for windows nt, windows 2000, windows 2003, windows xp. Features a collection of resources and magazines for windows IT professionals.
  
  
  Advanced Search 


September 19, 2006

How can I disable the caching of failed DNS lookups?

A Web Exclusive from FAQ for Windows
Jerold Schulman
DNS
InstantDoc #93540
FAQ for Windows
Email this Article
Printer Friendly
Reader Comments
Digg This
Del.icio.us
RSS
Subscribe to Windows IT Pro | See More Domain Name System (DNS) Articles Here | Reprints | Or get the Monthly Online Pass—only $5.95 a month!

10829 » How can I disable the caching of failed DNS lookups? (19-Sep-06)

Windows 2000, Windows XP, Windows Server 2003, and future Windows Operating Systems added the ability to cache DNS lookup results in the client's cache. This lowers the activity on the LAN and on the Web, but if a failed query is due to incorrect configuration, the client must use ipconfig /flushdns to remove it from the cache once fixed.

NOTE: To see the cache, type ipconfig /displaydns in the CMD.EXE window. You will see a display like:

Windows IP Configuration

         www.scrubtheweb.com
         ----------------------------------------
         Record Name . . . . . : www.scrubtheweb.com
         Record Type . . . . . : 1
         Time To Live  . . . . : 2802
         Data Length . . . . . : 4
         Section . . . . . . . : Answer
         A (Host) Record . . . : 66.93.156.37

         pagead.l.google.com
         ----------------------------------------
         Record Name . . . . . : pagead.l.google.com
         Record Type . . . . . : 1
         Time To Live  . . . . : 121
         Data Length . . . . . : 4
         Section . . . . . . . : Answer
         A (Host) Record . . . : 64.233.169.104

         ns02.penton.com
         ----------------------------------------
         Record Name . . . . . : ns02.penton.com
         Record Type . . . . . : 1
         Time To Live  . . . . : 81145
         Data Length . . . . . : 4
         Section . . . . . . . : Answer
         A (Host) Record . . . : 63.167.165.7

         .... snip ......
If you wish to avoid caching failed DNS lookup results, you can set the NegativeCacheTime Value Name, a REG_DWORD data type, to 0 at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters using PolicyMaker™ Registry Extension freeware, or you can include the following in a Startup script:
REG.EXE ADD HKLM\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters /V NegativeCacheTime /T REG_DWORD /F /D 0
NOTE: REG.EXE is built into Windows XP, Windows Server 2003, and later operating systems, or installed from the Windows 2000 Support Tools.


End of Article

Reader Comments

You must log on before posting a comment.

If you don't have a username & password, please register now.




Top Viewed ArticlesView all articles
Friday at PASS Europe 2006

Kevin talks about the closing day of the event and shares a funny Microsoft film. ...

PsExec

This freeware utility lets you execute processes on a remote system and redirect output to the local system. ...

Escape From Yesterworld

Kevin points you to the funniest SQL Server website ever! ...
Related Events Check out our list of Free Email Newsletters!
Related Resources Become a VIP member of the Windows IT Pro community!
Get it all with the VIP CD and VIP access. A $500+ value for only $279!

Subscribe to Windows IT Pro!
Solve your toughest technical problems with our experts and access 10,000 + articles online. 30% off

Monthly Online Pass - Only $5.95!
Get instant access to 10,000+ articles from Windows IT Pro Magazine!

TechNet Virtual Labs
Evaluate and test Microsoft's newest products.



ADS BY GOOGLE

Job Openings in IT SPONSORED LINKS FEATURED LINKS
Register for Orion NPM v9 - Evaluation
Affordable, easy-to-use network performance management with SolarWinds Orion – Free Trial!

Want a Hardware-Independent Image?
Binary Research, the Ghost people, shows you how to clone with 1!

Maximize speed, performance and reliablity of your PCs and servers—automatically!
Speed Up Your PC! Try Diskeeper 2008 with InvisiTasking Free Now!

Order Your Fundamentals CD Today!
Register today for your in-depth copy of one of three Fundamental CDs on the following topics – Exchange, SQL, and SharePoint.

Implement a Successful Archiving Solution
View this web seminar to learn the best practices for creating an email archive that is secure, compliant, and searchable.
Protect Your Company’s Digital Assets
Do you know the risks of sending important files over email or FTP? Read this white paper to learn what you can do to safeguard your company’s data.

Prepare Yourself for Exchange Catastrophe
Read this white paper to learn how you can keep Exchange server healthy, as well as predict and respond to server failure.

Boost Customer Confidence and Satisfaction
Read this eBook to learn how faxing can ease communication with less computer-savvy customers while reducing your security, compliance and support woes.
Windows IT Pro Home Register FAQ for Windows WinInfo News
Europe Edition About Us Contact Us/Customer Service Media Kit Affiliates / Licensing  
SQL Server Magazine Office & SharePoint Pro Windows Dev Pro IT Job Hound ITTV
IT Library Technology Resource Directory Connected Home Windows Excavator Windows SuperSite 
 
 Windows IT Pro is a Division of Penton Media Inc.
 Copyright © 2008 Penton Media, Inc., All rights reserved. Terms and Use | Privacy Statement | Reprints and Licensing