I did a series of upgrades from 10.04 to 12.04 on a VM under Xen virtualisation. Now for some reason eth0 won't start up, ifconfig says mac address is 00:00:00:00:00:00, I've tried setting the address but the network still refuses to come up.
I've rebooted into DSL and managed to run ifconfig, and this is the result
Something in the new release broke networking. How can I find out what?