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how do you remove stale information? RRS feed

  • Question

  • Windows Server 2008 R2

    i have both DHCP, DNS on my DC servers. our DHCP leases expires in 8 days. the problem is in DNS, i usually find computers that have old IP addresses still lingering causing confusion among the support staff when they do remote connections.

    how does one make sure when DHCP leases expire, the DNS entries also gets removed? or updated?

    Monday, March 28, 2016 12:16 PM

Answers

All replies

  • Hi,

    You need to consider adjusting lease duration or aging/scavenging configuration (I would recommend one of those). Or you can configure DHCP to register DNS records on behalf of the clients. This should solve the issue.

    Please see https://blogs.technet.microsoft.com/askpfe/2011/06/03/how-dns-scavenging-and-the-dhcp-lease-duration-relate/ for a detailed explanation of why this happens and options you may choose to fix that.

    Regards



    • Edited by Avendil Monday, March 28, 2016 3:01 PM
    • Proposed as answer by Mr XMVP Monday, March 28, 2016 9:54 PM
    • Marked as answer by Reno Mardo Tuesday, March 29, 2016 4:57 AM
    Monday, March 28, 2016 2:58 PM
  • holy smokes! as the link, that's exactly is what is happening. seems like a classic case.

    thanks!

    Monday, March 28, 2016 3:11 PM
  • Please don't forget to mark the reply as an answer if it helps:)
    Monday, March 28, 2016 3:18 PM
  • Hi Reno Mardo,

    Avendil has provided two good ways to solve the problem: DNS scavenging and use DHCP to register DNS for clients.

    If you want to use DHCP to register DNS records on behalf of clients, you may check the following screenshot:

     

    In DHCP scope properties> DNS, check "Discard A and PTR records when lease is deleted", then when the lease time is expired, the DNS records will be deleted on DNS too.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    Tuesday, March 29, 2016 2:13 AM
    Moderator
  • hi Anne,

    my DHCP dns settngs are like that in the picture. all defaults except the lease period which is 8 days.

    DNS scavengenging was the default of 7 days which i also thought is too close to the DHCP lease period so i made it to 1 day only. still having stale DNS clients/info.

    today i made DNS scangenging to 3 days. DHCP lease still on 8 days.

    Tuesday, March 29, 2016 4:57 AM
  • i mark it as answer only because there's no partial answer selection :)

    will see after a week.

    Tuesday, March 29, 2016 4:58 AM
  • Hi Reno Mardo,

    This article might be of help if you are confused about how to configure DNS scavenging parameters:

    Configuring Scavenging Parameters:

    https://technet.microsoft.com/en-us/library/cc959286.aspx

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Tuesday, March 29, 2016 6:21 AM
    Moderator
  • hi Anne,

    not really confused but still aiming for the sweet spot on scavenging. thanks for the link though.

    Tuesday, March 29, 2016 6:28 AM
  • Hi Reno,

    If you still have questions, feel free to ask.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Friday, April 1, 2016 2:26 AM
    Moderator
  • hi,

    my DNS and DHCP settings are as per what others have recommended. waiting a few more days to see if would still get stale information.

    Sunday, April 3, 2016 5:41 AM