I went from ArchLinux to Ubuntu on my dev box. I use VirtualBox to test web sites on Windows and IE. I have my Windows 7 VirtualBox image running on Ubuntu's VirtualBox. Back with ArchLinux, internet worked "out of the box" on the Windows boxes. I left the default options on the box's Network Options (NAT).
The Windows machine shows as "connected to ethernet" but reports:
The dns server isn't responding
So I can't access Internet from there. I tried searching for Ubuntu's official docs but they seem pretty outdated. I tried using my old boxes from Arch (which boot normally but have no internet) and creating a new box from Ubuntu itself, but still get the same results.
Update: I'm using VirtualBox 4.1.18 from Ubuntu's repository (apt-get install virtualbox).