For all you folks starting with networking I would like to highlight this very simple game from Cisco. After few rounds you will be rock solid on this topic. Enjoy and as always have fun.
Subnetting is fundamental skills that every network “pro” should know. For everyone that want to get better while having fun there is superB game from Cisco called Subnet Game. It requires a cisco login, if you don’t have one just take some extra minutes it is worth it!
In this game you are a secret agent and your mission is to subnet Area 51, so expect some alien high tech stuff, go and show them who is the boss.
Few years back when I was god damn kid a friend of my told me about the site hellboundhackers.org. This site is so much fun. Besides large article base, it has numerous security challenges in different areas, from basic web hacking, java script hacking, encryption, timed, real world and steganography are on the list.
Going through the challenges teaches you about different vulnerabilities that are out there. And how to fix them – application patching challenges.
So go now, learn and exploit them already!