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Domain Controllers unresponsive - network issue RRS feed

  • Question

  • We have recently faced a very strange issue that all of our windows 2008 r2 domain controllers were not authenticating to clients. Upon investigating we found that we can not ping any of the domain controller and getting request time from all domain controllers. We have 2 sites. Site A has 1 physical DC with all fsmo roles and 1 virtual DC running on Hyper-V. Site B have 2 DCs running on hyper-V host. During this issue we were able to ping other VMs running on same host. All 3 DC vm and 1 physical DC wasnt responding. We rebooted physical and virtual both domain controllers but issue reappeared after 3 to 4 minutes. Then we rebooted them again but before that we unplugged ethernet cable from physical server and disabled virtual NIC from VM. After that all were working perfectly. We couldnt find that cause that why it happened? We are using trendmicro endpoint security. Scanned all 4 DCs but it couldnt find anything. Event logs were showing errors of ADWS 1206 and other directory services and DNS errors. How can we find the root cause of this issue and avaoid from this happening again? 
    Tuesday, July 9, 2019 9:54 AM

All replies

  • Hello,
    Thanks for posting in our forum.

    >>We rebooted physical and virtual both domain controllers but issue reappeared after 3 to 4 minutes.

    >>We are using trendmicro endpoint security. Scanned all 4 DCs but it couldn't find anything.

    According to my experience, the issue may occurred due to windows firewall or other Security software. In order to narrow down the issue, please check windows fire wall setting and try to disable TrendMicro endpoint Security temporally to see if it helps.



    Best Regards,
    Daisy Zhou

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

    Wednesday, July 10, 2019 5:34 AM
    Moderator
  • Hello,
    If this question has any update or is this issue solved? Also, for the question, is there any other assistance we could provide?


    Best Regards,
    Daisy Zhou

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

    Friday, July 12, 2019 10:21 AM
    Moderator
  • Hi,
    I am just writing to see if this question has any update. If anything is unclear, please feel free to let us know.
    Thanks for your time and have a nice day!


    Best Regards,
    Daisy Zhou

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

    Monday, July 15, 2019 8:35 AM
    Moderator