[SOLVED] Win2019 VMs losing network connectivity

[AraToken]

@merkkg thank you for your response. Great to hear that your issue seems so far resolved!
Can you maybe tell me if you installed specific drivers from the virtio disk? Or only the network driver? I already installed the redhat Driver for my network interface because without it i couldn't get my network to function at all.

Isn't the Qemu Guest Agent only a monitoring client? Or does it come with additional drivers for windows that may be related?

Best regards

 

[merkkg]

@AraToken I mounted the disk image and tried to run the installed but it seemed to failed so then from device manager I checked for any hardware that had no divers installed and searched the mounted disk including subfolders.

if you show me device manager can see if any devices don't have drivers.

 

[AraToken]

The thing is that my boxes doesn't show any "missing devices". Even the "PCI simple communications controller" mentioned in the QEMU-Guest Agent Wiki page was not missing on any of my VMs.

I already tried to let windows search for drivers on my virtio disk but there seem to be no "newer" drivers.
What version of virtio-disk did you use? I'm not sure if the current version does ship with different drivers than for example my version 0.1.217.

 

[AraToken]

Hello,
it appears that we finally found the solution for the disconnects on our windows machines.
Apparently the reason why the VMs lost connection was because of a combination of IPv6 and the NCSI service of windows. I noticed that NCSI triggered during the times when the network connection was lost but i wasnt sure if that was the cause or the symptom of it.
IPv6 is on our machines disabled by default and i just happened to activate v6 on our network adapter to "just try it".
Ever since i enabled v6 there were no furhter incidents for weeks now.
I still dont know the details of how or why but i might now count this post as solved because in the end it does not seem to be a proxmox related issue.
Thanks again for anyone responding to this!