KVM VM lost its public IP and access to the internet after reboot?

Question

I have shut-downed one of the VMs with "virsh shutdown VM" and when I started it, it lost its access to the internet. The VM had its own pupblic IP that had its own interface. I'm not sure how this public IP was given to the VM, probably from KVM host, but I don't see it in history. Any good way to start debug this?

Answer 1

You didn't mention what the guest OS is nor how the disk is passed to the VM, so assuming it's linux and speaking generally I would mount the guest's disk from the host (either with mount or guestfish, depending on how the disk is passed) and see what's in the /etc network configuration. If you figure out how the address was obtained, you will know where to look first. Also see if the network interfaces defined for the VM (virsh domiflist <name>) are still available in the host machine. That's for a start.