Following the instructions in Lesson 13, I installed my networked LaserJet 2100 this morning. The only change I made was on page 94 where I changed "socket://192.168.0.12:9100" to "socket://192.168.1.254". The latter is the IP address of my networked print server.
The only other problem was my version of the 2100 was not listed so I had to guess. It worked, so I won't tinker with it.