I use Linux on the desktop (currently Ubuntu), but occasionally need to use Windows for things like webinars, OS-specific testing, etc. I started using VirtualBox for virtualization around six months ago, and have been reasonably satisfied; Windows boots quickly, and everything "just works." That is, until yesterday.

I was given a linux VM image running a web server and some applications I needed to review. On top of that, I needed to do so over WebEx, so that I could share my screen with somebody else. This meant I needed the following to work:

1. Internet access for my Windows VM
2. Access to my linux VM from my Windows VM
3. Ideally, access to both guest VMs from my linux host
4. Ideally, internet access for my linux host