I am currently taking this course and indeed it is an excellent course. I am having problem completing exercise 23 & final challenge. If any who has taken this course would like to share information regarding these two exercises, I have enclosed my email below.

Jack

busana100@yahoo.com

The Prereq's for the course include:

•The student must have a solid understanding of Network Administration and TCP/IP, and a reasonable level of familiarity with Linux, in order to complete the course.
• A modern PC, with the capability of displaying full screen video and sound.
• A fast Internet connection to view or download the Videos.
• A fast Internet connection to connect to the Offensive Security Labs over VPN.

And of course I'm quoting that directly out of the Offensive Security 101 v2 Course Description that can be found below:
http://offensive-security.com/documentation/offensive-security.pdf

Judging from your experiance, I bet you'd do fine.

For the offensive-security 101 v2 standard price is $550.
http://offensive-security.com/training.php
Your plan to study more in tcp/ip is definitely a good idea considering if you look around these forums on where people ask "where should I start?", etc, everyone does recommend getting a good grasp on Tcp/Ip.