Upon installing Alpha 1 of Karmic Server, I faced a unique problem in that it was unable to connect to the internet.
Matt told me to use the following tools to diagnose the problem:
lspci (to look for a working Ethernet controller)
modprobe (to make sure the module is installed correctly)
ifconfig (to read actual network interface info)
From lspci's output, I could tell that there was an Ethernet controller installed.
Unfortunately, I still couldn't connect to the internet, and ifconfig showed only the loopback device as functioning.
I looked in /etc/network/interfaces to see if eth0 initialized and, from its contents, I had a sneaking suspicion that it had not:
iface lo inet loopback
I added the following lines underneath:
iface eth0 inet dhcp
Everything works fine now. Sweet...