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Clear the DNS cache on all active directory integrated DNS server once a day

Question

Wednesday, October 2, 2013 7:40 PM

HI

I am running on windows 2008 R2 ADDNS.

I need script to clear cache from DNS server once in a day. Please suggest..

All replies (3)

Thursday, October 3, 2013 12:59 PM ✅Answered | 1 vote

I see. The command I provided will do the trick. Here is the DNSCMD command syntax that you can put into a batch file, and run remotely using PSEXEC from your own desktop.

psexec \DNS-Server-01 dnscmd /clearcache
psexec
\DNS-Server-02 dnscmd /clearcache
psexec
\DNS-Server-03 dnscmd /clearcache
etc ...

DNSCMD:
http://technet.microsoft.com/en-us/library/cc772069.aspx

PsExec v1.98
http://technet.microsoft.com/en-us/library/cc772069.aspx

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You can also use copy that command into notepad, save it as a bat file (such as clearcache.bat), then copy it to all DNS servers, then create a scheduled task on each server to run it on a schedule of your choosing. You can also get creative and just place it on your own machine, create a scheduled task using PSEXEC to run it remotely on all DNS servers.

Schedule a Task:
http://technet.microsoft.com/en-us/library/cc748993.aspx

Ace Fekay
MVP, MCT, MCITP/EA, MCTS Windows 2008/R2 & Exchange 2007, Exchange 2010 EA, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Technical Blogs & Videos: http://www.delawarecountycomputerconsulting.com/

This post is provided AS-IS with no warranties or guarantees and confers no rights.


Thursday, October 3, 2013 2:12 AM | 1 vote

You can use dnscmd**  /**clearcache.

Curious, why do you need to clear the cache? I have customers that have DNS running for the past 6 months without requiring to clear the cache. Are you seeing errors or having a problem? If yes, please elaborate and we'll try to assist you.

Ace Fekay
MVP, MCT, MCITP/EA, MCTS Windows 2008/R2 & Exchange 2007, Exchange 2010 EA, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Technical Blogs & Videos: http://www.delawarecountycomputerconsulting.com/

This post is provided AS-IS with no warranties or guarantees and confers no rights.


Thursday, October 3, 2013 9:41 AM

Required a script that will clear the DNS cache on all domain controllers once or twice a day. 
Last month, the NYtimes.com site was hacked and name servers were taken over and redirected to a unknown group. 

The normal cache clearing didn’t happen because the name servers were taken over and set themselves as authoritative. Windows DNS normally clears non-authoritative names every 24 hours.