SBS 2011 Std - Slow DNS Response


  • Hi,

    I have taken on support for an fairly new SBS2011 Std Server. The previous company had done some very strange things with the setup; all but 1 is now resolved.

    I have an issue where the server (sometimes) takes ages to respond to DNS queries. More often than not, the server will take around 20 seconds to respond to any name even 'localhost'!
    The issue affects netbios names 'Server' and FQDN 'Server.domain.local'.
    The DNS on the local NIC is set to the server using full address not loopback address. The DNS Service is using forwarders in it's configuration.

    Here's the really odd bit;
    When making some small changes it starts to work correctly but after a couple of minutes it slows down again. Even restarting the service is no fix.
    If i open a command windows and do 2 lookups both windows wait then respond at the same time (like it's trying something, then giving up and responding to all requests simultaneously).

    Any help would be greatly appreciated.



    Monday, June 18, 2012 11:54 AM

All replies

  • Some additional info might help.... errors in the event logs? 

    Have you downloaded, installed, allows WSUS to update, then run the SBS 2011 BPA?  If not, do so and fix anything it finds.

    From a command prompt:  ipconfig /flushdns then ipconfig /registerdns

    Not sure I have seen this on Server 2008 R2, but perhaps DNS scavaging might bring it into shape.

    And, of course, don't forget the Fix My Network Wizard.

    Larry Struckmeyer[SBS-MVP]

    Monday, June 18, 2012 12:01 PM
  • I will have to contact the site and come back to you, I know I have done the flushDNS and registerdns, also installed and ran the BPA (nothing found).

    I'm sure the event log was clear, but I will double check.
    I will also run the fix my network wizard again.


    Monday, June 18, 2012 2:42 PM
  • OK so I've just had contact with the customer and they are suggesting that this issue is now resolved.

    I think that the fix may have been changing the node type to Broadcast. I also cleaned up some unrequired entries in DNS for their external website ect.
    Either way the fix didnt work immediatly and took a couple of days to go through.

    I will update again if anything changes.

    • Marked as answer by Kyonet-IT Wednesday, June 20, 2012 8:23 AM
    • Unmarked as answer by Kyonet-IT Tuesday, August 07, 2012 10:14 AM
    Wednesday, June 20, 2012 8:23 AM