+ Post New Thread
Results 1 to 10 of 10
Windows Thread, DNS issues in Technical; I've run netdiag on both my DC and all looks ok. However I still seem to get machines resolving wrongly. ...
  1. #1

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    13,572
    Thank Post
    721
    Thanked 1,683 Times in 1,498 Posts
    Rep Power
    432

    DNS issues

    I've run netdiag on both my DC and all looks ok.

    However I still seem to get machines resolving wrongly.

    Today I pinged a laptop T1-15 which was not connected to the network as I was trying to sort the wireless out.

    Yet it responded as the ip address dns said that this laptop has is in use by another pc.

    Ben

  2. #2

    Join Date
    Sep 2007
    Posts
    90
    Thank Post
    7
    Thanked 32 Times in 17 Posts
    Rep Power
    20
    sounds like your DHCP and DNS server(s) are "out of sync", possibly due to
    aging and scavenging being configured incorrect.
    Check this kb article:
    How DNS dynamic updates work together with the DNS "aging and scavenging" process in Windows 2000 and in Windows Server 2003

  3. Thanks to rvdmast from:

    plexer (16th September 2008)

  4. #3

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    13,572
    Thank Post
    721
    Thanked 1,683 Times in 1,498 Posts
    Rep Power
    432
    Had a quick scan of that article what the best practice to set dhcp and dns to then?

    Ben

  5. #4

    Join Date
    Sep 2008
    Location
    Edinburgh
    Posts
    12
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Well, ideally you wouldn't need scavenging but removal of records just doesn't work as well as the registration.

    I take it your lease duration is 8 days and your refresh and no-refresh are 7?

  6. #5

    Join Date
    Sep 2008
    Location
    Edinburgh
    Posts
    12
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    PS - it could be WINS if you're still using that.

  7. #6

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    13,572
    Thank Post
    721
    Thanked 1,683 Times in 1,498 Posts
    Rep Power
    432
    no wins.

    Lease is 5 days.
    Enable DNS dynamic updates according to the settings below is checked
    Always dynamically update dns a and ptr records is now checked other option was checked before.
    Discard a and ptr records when lease is deleted is checked
    dynamically update dns a and ptr records for dhcp client that do not request updates is checked.

    Ben

  8. #7

    Join Date
    Sep 2008
    Location
    Edinburgh
    Posts
    12
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    I take it you have you checked for and confirmed the presence of duplicate records in DNS already?

    If so, have you now enabled scavening?

  9. #8

    Join Date
    Sep 2007
    Posts
    90
    Thank Post
    7
    Thanked 32 Times in 17 Posts
    Rep Power
    20
    I believe the rule of thumb was that the sum of the DNS refresh- and no-refresh interval should equal the DHCP lease duration.

  10. #9

    Join Date
    Sep 2008
    Location
    Edinburgh
    Posts
    12
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    I can't make much sense of that rule myself. Could you go into why it should be set that way?

    The MS default settings put the refresh and no-refresh intervals at 87.5% of the DHCP lease duration which makes a lot of sense. The DNS server isn't pestered with unnecessary traffic for the majorify of the duration of the lease.

  11. #10

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    13,572
    Thank Post
    721
    Thanked 1,683 Times in 1,498 Posts
    Rep Power
    432
    Scavenging is enabled and always has been I'm not quite sure what the interval for that should be.

    Ben

SHARE:
+ Post New Thread

Similar Threads

  1. DNS Flush / DNS Register
    By brahma in forum Windows
    Replies: 1
    Last Post: 18th July 2008, 09:29 AM
  2. DNS Problems... DCHP correct, DNS wrong
    By burgemaster in forum Windows
    Replies: 7
    Last Post: 27th June 2008, 11:05 AM
  3. DNS/DHCP Issues
    By link470 in forum Windows
    Replies: 1
    Last Post: 11th March 2008, 08:33 AM
  4. DNS Issues
    By FN-GM in forum Windows
    Replies: 14
    Last Post: 18th January 2008, 06:01 PM
  5. Interesting DNS issues
    By mortstar in forum Wireless Networks
    Replies: 3
    Last Post: 23rd January 2007, 04:06 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •