virtualbox.org

Virtual Box Version: 5.2.12
Host: Windows 10 64 Bit (Build 1803)
Guest: Windows 10 64 Bit (Build 1803)

Three times now I have had DNS completely break in a Windows 10 guest when the host lost power unexpectedly. Everything else works perfectly and you can ping the DNS server but it just can't resolve anymore.

I have tried every thing I can think including but not limited to restarting, renewing the ip config on the virtual adapter, flushing dns, re-registering dns, removing and replacing the virtual adapter in the guest settings, changing to a different adapter, rebuilding the IP stack on the guest.

The only way I can ever fix it is to back up my data from the guest, wipe and re-install everything which is an absolute PITA!

If anyone has experienced this problem on a guest vm or on a real computer and found a fix that works for them please reply.

Your post is thin on details. Like what's your network mode (HostOnly, NAT, NATservice, Bridged, Internal, etc.). Like your network setup. Like the output of "ipconfig -a" from both host and guest. Like who's your DNS server; is it your ISP's, a 3rd party? Who's doing the caching?

And I got to admit that powering everything down and the entries not being reset is something that I've never heard of. I won't even go to the fact that you have to re-install the OS, that's borderline science fiction, the Twilight Zone...