Comment 18 for bug 1881832

So I'm on Ubuntu server 20.10 guest on KVM host (currently Unraid). I should mention that I'm not using virtio network but I have passedthrough my physical Intel network card.

I'm not getting ipv4 on boot, only ipv6.
After it's booted I can log in and simply renew dhcp using dhclient command. And it works finr I'm finally getting ipv4 from my DHCP server on the network.

Now I didn't have any problems with netplan config file. Device name was correct and corresponded with my current device name - in my case enp3s0.

I did not remove iso after install as this KVM host will not boot from ISO after installation. I have removed it asfter few reboots to see what will happen and - nothing chnaged my network interface is still enp3s0.

So tu summarise, this issue might not be exactly related to config in netplan. As it seems to be all in order in my installation. But still I'm not getting ipv4 at boot. Well it happened maybe once or twice when on boot it got ipv4. Maybe 1 in 10/15 reboots.

ps. I have cteared 3 VM's with same ubuntu 20.10 iso, with 3 different physical NIC's passed to VM. Same problem on each machine.

It's surprising to see that's it's happening since over six months. Is seems like it came with one of kernel updates.