如何将虚拟机从VMWare移植到VirtualBox？

I've been using VMWare for a while and am very happy with it, but I would like to compare it with VirtualBox. Apparently the disk images are compatible, and I have successfully booted my Fedora based VM created by VMWare in VirtualBox... but the network is completely unavailable. How do you port a virtual machine from VMWare to VirtualBox and keep all the capabilities intact?I've been using VMWare for a while and am very