I have Ubuntu guest OS in VirtualBox using default NAT for eth0.
Works fine at the office and at home EXCEPT when on office VPN from home.
When the host OS (Windows 7) is connected to the VPN, DNS lookups don't work within the Virtualbox guest. DNS lookups are fine on the host. Within Virtualbox, I can ping IPs directly both within the VPN and the outside, so it's not a connectivity problem.
It looks like the Ubuntu guest is using localhost as the DNS entry point, according to
nslookup. So it looks like something locally is then dispatching to other underlying DNS.
How do I troubleshoot this?