My Hyper-V host is an Intel i7 machine with Windows 10 v2004, fully updated. I installed Docker Desktop for Windows newest version just yesterday, think it was v18.104.22.168. I have never used Docker before. After reboot I cannot connect to Hyper-V virtual machines with Vmconnect.exe (the “Connect” choice in Hyper-V manager) anymore.
Click Connect in Hyper-V manager, the vmconnect window opens with status “Connecting to ‘vmname’…”, after 1-2 minutes it times out with “Cannot connect to the virtual machine. Try t connect again. If the problem persists, contact your system administrator. Would you like to try connecting again?”
I can still connect with RDP but it cannot be used if the guest vm does not have networking, in that case Vmconnect is the only way to connect to a Hyper-V vm. So the issue is quite serious, I have “lost” one VM already not being able to connect to it at all.
I have googled everything I can. Tried changing port from 2179 to 21791, and back. Tried other registry settings, and back when they didn’t help.
Wireshark does not show any traffic from the vm host, 192.168.100.100, to any guest vm port 2179 (or 21791 when trying with that) in the same /24, when trying to connect with Vmconnect. Wireshark capture filter: port 2179 (or 21791).
Only port 2179 captured packets are something that look like self connects within the various Hyper-V virtual adapters in 172.16.0.0/12 range. I’m not a network pro so no idea what this means. The route table looks sane, default route 0.0.0.0/0 metric 11, 192.168.100.0/24 metric 21, everything else has a higher metric. The interface is correct.
Hyper-V virtual switch has no problem, VM’s are able to connect to internet when being RDP’d to. It is not the default switch but a created one, external network, allow mgmt os.
I have now uninstalled Docker Desktop for Windows and rebooted several times, but the problem persists. And no I don’t have backups up to the moment of installing Docker. My bad. But this really is not what one would expect to happen.