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dhcp 2012r2 failover RRS feed

  • Question

  • Hi,

    I configured hot/standby between 2 dhcp server.

    1. On some scopes I see partner giving out some ip addresses even though from what I understand unless primary server is unavailable it shouldn't do that. Is that expected ?

    2. I'm getting 20291 event logged. about 6  within 3 hours span. I already have KB 2919355 installed (it was installed before dhcp role was installed on both servers). Is there any resolution around that

    thanks


    • Edited by Halo-NEXT Tuesday, March 20, 2018 11:54 PM
    Tuesday, March 20, 2018 7:59 PM

All replies

  • Hi,

    Have a nice day! Thanks for your question.

    According to your description, my understanding is that DHCP failover with load sharing mode, Event Log displays numerous Event ID: 20291, and the error repeats repeatedly for the same IP.

    Meanwhile, please try to update KB2955135 on the DHCP servers.

    Besides, as KB2955135 mentioned that Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. If both servers are Windows Server 2012 R2, please install KB3000850 (November 2014 update rollup for Windows Server 2012 R2), download link:
    http://www.microsoft.com/en-us/download/details.aspx?id=44975

    Note:
    Before you install this update, you have to first remove the failover relationship, install the update to both DHCP nodes and restart them, and then reestablish the failover relationship.

    For your first problem, in theory, the partner would not lease IP addresses for clients while primary DHCP is available. Did these leased addresses come from the same scope?

    Here is the links refer to DHCP failover communications, it may be helpful,

    DHCP Failover Communications

    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn338987(v=ws.11)

    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn338973(v%3dws.11)

    Highly appreciate your successive effort and time. If you have any questions and concerns, please feel free to let me know. I look forward hearing from your good news.

    Best regards,

    Michael


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    Wednesday, March 21, 2018 9:12 AM
  • Hi,

    How are things going on? Was your issue resolved?

    Please let us know if you would like further assistance.

    Wish you have a nice weekend!

    Best regards,

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Friday, March 23, 2018 9:54 AM
  • Hi,

    How are things going on? Was your issue resolved?

    Please let us know if you would like further assistance.

    Wish you have a nice day!

    Best regards,

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com


    Monday, March 26, 2018 9:43 AM
  • Do I deleted relationship by going into IPv4 -> properties -> failover tab and click delete? 

    I'm seeing on some scopes IP leased by stand by server while on others I don't see it. I'm looking at display statistics and at Address Granted by this server pool and Addresses Granted (Partner Pool)

    From what it looks like KB2955135 was rolled into 3000850 rollup. I'm I wrong about that? If so I have KB3000850 installed on both servers





    • Edited by Halo-NEXT Wednesday, March 28, 2018 12:07 AM
    Tuesday, March 27, 2018 10:16 PM
  • Hi,

    Sorry for my delay.

    Please uncheck "Reuse existing failover relationships configured with this server (if any exist) "When creating new partner DHCP for failover as the following exhibit.

    More detailed information regarding deleting a DHCP failover relationship, please refer to the following article,

    https://kx.cloudingenium.com/microsoft/servers/windows-servers/delete-dhcp-failover-relationship-partner-server-unreachable/

    Besides, if you configure DHCP failover mode with "Hot standby" and the option "Active", the partner DHCP will offer IP addresses for clients requesting.

     

    Hope above information can help you.

    Highly appreciate your effort and time. If you have any questions and concerns, please feel free to let me know.

    Best regards, 

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Friday, March 30, 2018 2:05 AM
  • Hi,

    How are things going on? Was your issue resolved?

    Please let us know if you would like further assistance.

    Wish you have a nice weekend!

    Best regards,

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Sunday, April 8, 2018 5:57 AM
  • Hi,

    How are things going on? Was your issue resolved?

    Please let me know if you would like further assistance.

    Wish you have a nice day!

    Best regards,

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Monday, April 23, 2018 12:53 PM