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M Gibson's avatar
M Gibson
Copper Contributor
Nov 17, 2018

Windows 10 1803 to 1809 Hyper-V - Cannot connect to the virtual machine

Windows 10 1803 to 1809 Hyper-V - Cannot connect to the virtual machine Hi all, After upgrading from Windows 10 1803 to 1809 I am no longer able to connect to any running VM's. I am able to start ...
Vic_U's avatar
Vic_U
Copper Contributor
Oct 23, 2019

AMoeller88 That doesn't work for me, unfortunately.

M Gibson's avatar
M Gibson
Copper Contributor
Aug 18, 2020

Vic_U I know this is an old thread I initially started, but I had the exact same issue migrating from Windows 10 1909 to 2004.

 

I did come across an article with a registry fix, changing the ListenerPort dword from 2179 to 21791 under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization. After stopping/started the hyper-v windows services I was able to connect to the virtual machines as normal.

  • Maitre Elias's avatar
    Maitre Elias
    Copper Contributor
    Jan 06, 2021

    M Gibson correct and thanks for this fix, I changed the ListenerPort dword from 2179 to 21791 and was able to access the new VM. I have the most update-to-date win10 20H version.

    Can somebody from MS indicate why this happens from time to time and if we should keep this different port?

    • M Gibson's avatar
      M Gibson
      Copper Contributor
      Jan 06, 2021

      Hi Maitre Elias I believe its to do with the reserved ports within Windows. Hyper-V seems to aggressively reserve a large range of ports.

       

      At a command prompt, if you type netsh int ipv4 show excludedportrange protocol=tcp it will show the port exclusions. One of which is a range which contains port 2179.

       

      You can run netsh int ipv4 set dynamic tcp start=51001 num=5000 which will reset the dynamic port range to start at 51001 which is a range applications typically have no port reservations to bind to.

       

      Followed by running reg add HKLM\SYSTEM\CurrentControlSet\Services\hns\State /v EnableExcludedPortRange /d 0 /f which disables the HNS (Windows Container Host Networking Service) port exclusion behaviour.

       

      Set your Hyper-V port back to the original value of 2179 and reboot your computer. You should now be able to launch Hyper-V, start a VM and connect to it.

       

      Hope this helps you and others. Here are the links to the sources on the issue/fix:

      https://hungyi.net/posts/wsl2-reserved-ports/

      https://github.com/docker/for-win/issues/3171

      https://stackoverflow.com/questions/48478869/cannot-bind-to-some-ports-due-to-permission-denied/62359555#62359555

       

      • Maitre Elias's avatar
        Maitre Elias
        Copper Contributor
        Jan 06, 2021

        M Gibson so many thanks, I will do but I have one concern, I use docker desktop on the win 10 box, so if I disable the HNS port wouldn't this affect how containers/docker work?

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