Networking lost when cloning Ubuntu image

I use Microsoft Virtual Server 2005 R2 to host a couple of server. I have become accustomed to having template virtual machines so I don’t have to start from scratch for every installation. When I did that to a newly installed Ubuntu 7.10 I immediately noticed that I lost all networking.

It turns out that Ubuntu 7.10 has moved some settings for MAC address mapping for interfaces to the file /etc/udev/rules.d/70-persistent-net.rules. Edit that file and make sure that the MAC address matches the MAC address given by the virtual host.