ML
    • Recent
    • Categories
    • Tags
    • Popular
    • Users
    • Groups
    • Register
    • Login

    Solved Server Losing Connection to AD DC Intermittently

    IT Discussion
    active directory windows windows server 2012 r2 hyper-v hyper-v 2012 r2 networking ad dc
    2
    3
    1.4k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • scottalanmillerS
      scottalanmiller
      last edited by

      Two Windows Server 2012 R2 VMs on the same Hyper-V 2012 R2 host, one is a dedicated Active Directory Domain Controller. The other is an app and file server. There are gobs of resources, this is a way overbuilt host. The physical host has 20 physical cores, 40 virtual threads. The DC has two vCPU assigned. The app server has ten vCPU assigned. Both have plenty of RAM. The DC has 6GB, and the App Server has 64GB. The physical has 128GB. We can't find any constrained resources anywhere.

      From time to time, a few times a day, we get an error from both systems that try to mount drives from the app/file server, and we can see the matching error in that server itself, that connections to the DC have been lost and no DC can be found.

      Screenshot from 2019-04-12 17-00-15.png

      There is only one DC, but having two would likely just hide the problem.

      1 Reply Last reply Reply Quote 0
      • scottalanmillerS
        scottalanmiller
        last edited by

        Found it. There was a rogue DNS entry for an old domain controller lingering from long ago. So the app/file server would sometimes look up the domain and get the IP of a long dead DC that isn't around.

        1 Reply Last reply Reply Quote 4
        • wrx7mW
          wrx7m
          last edited by

          Good find.

          1 Reply Last reply Reply Quote 0
          • 1 / 1
          • First post
            Last post