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Lost connection to Domain (Active Directory & Internet) RRS feed

  • Question

  • Hello, I'm new here. Do correct me if I mess up. 

    There were 2 VMs in the Hyper-V on Server 2012. It was all good till I added one more VM from a virtual hard disk. When I turned the VM, I lost connectivity to the Sever machine (I was using RDP). I logged in to the machine physically and saw that the connection was broken. There's no hardware issues that I can think of. LAN cable is good and strong. 

    Physical NIC shows "Network cable unplugged" and virtual nic shows "Unidentified network". I used the External switch in Hyper V. 

    Also, I need the AD in the VMs to access network paths.

    It would be a LOT of help if you could give me a hand here.


    • Edited by leonnunwz0 Friday, May 15, 2020 3:06 PM
    Friday, May 15, 2020 3:05 PM

All replies

  • I'd check the domain controller is not multi-homed. Also check the domain controller and problem member both have the static ip address of DC listed for DNS and no others such as router or public DNS

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Friday, May 15, 2020 3:20 PM
  • Thanks for swift reply Dave, but I have no clue on what you said. Could you please dumb it down for me?

    I had even removed the virtual switch from Hyper V but it did 't work.

    Thanks, 

    Leon

    Friday, May 15, 2020 3:51 PM
  • It's not going to work without both VMs connected to an external vSwitch. Also please run;
    • Dcdiag /v /c /d /e /s:%computername% >c:\dcdiag.log
    • repadmin /showrepl >C:\repl.txt
    • ipconfig /all > C:\dc1.txt
    • ipconfig /all > C:\problemmember.txt

      then put unzipped text files up on OneDrive and share a link.

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Friday, May 15, 2020 3:59 PM
  • Hi Lenonnunwz,

    Please check if I understand the issue correctly. 

    When you add the third VM on the Hyper V host, you are unable RDP to the Hyper V host to manage it, and when you login the Host locally, you found the Hyper V host's network is broken.

    If I misunderstood it, please feel free to let me know.

    > It was all good till I added one more VM from a virtual hard disk. When I turned the VM, I lost connectivity to the Sever machine (I was using RDP). 

    How do you add the third VM, what do you mean from a virtual hard disk. Do you have VHD for a VM, and create a new VM from the VHD. If yes, what is the original VHD.

    Please try to turn off the third VM, and recreate the external virtual switch, check if it could work.

    Thanks for your time!

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help.
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    Monday, May 18, 2020 5:59 AM
    Moderator
  • "I logged in to the machine physically and saw that the connection was broken."- what does mean "broken"? Were there the two crossed red lines on the network icon or the yellow circle with the exclamation mark (as if there's an IP address error)?


    • Edited by MF47 Wednesday, May 20, 2020 3:20 PM
    Wednesday, May 20, 2020 3:19 PM
  • Hi Lenonnunwz,

    I'd like to check how things are going your side? If the above reply could be of help, please mark useful reply as answer, if you have any other concerns or questions, please feel free to feedback.

    Best Regards,

    Anne


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

    Thursday, May 21, 2020 6:02 AM
    Moderator