Mark and I went to help John, the paper millionaire of a dotcom, set up his home network. He has a cable modem and no static IP addresses so it's a matter of configuring a Linux box to act as a firewall and IP masquerading.
John, being a paper millionaire of a dotcom, can afford to buy insanely high end PC equipment and his primary box, dookey is an insanely high end PC. I don't remember the details off the top of my head, but it's this large box the size of a small refriderator you'd find in a college dorm room. And it's running Linux.
The installation went fine. The only problem we encountered was a problem in getting an IP address via DHCP from his cable provider. The problem ended up being his currently assigned IP address was bound to a MAC address from his Windows system, so we swapped the ethercards (not wanting to wait for the timeout period) and instantly we had a good connection.
Three commands later and we had IP masquerading working on Linux.
So after Mark and I helped John the paper millionaire of a dotcom get connected, I downloaded a network monitor I wrote and installed it on his system (some problems due to some changes in the way dlopen() works internally that I was relying on).
It was interesting to see some of the network activity he gets at his end of the connection. It seems his cable provider uses private IP addresses for something. I'm not sure all of what was flowing through since the monitor only shows packet headers and not the data, but it would be interesting to find out.