Cisco Graphical Network Simulator

To simulate a network, I came across a Graphical Network Simulator found at GNS3.net
There is a short tutorial on Youtube on how to setup GNS3 that can be found at 

• http://www.youtube.com/watch?v=5s1LHNUtzns
• https://www.youtube.com/watch?v=5-1KOCiLw-c

You will need Cisco IOS Images to run GNS3, that you can download at:

• http://sobek.su/Cisco/IOS/
• http://thepiratebay.org/torrent/4409592/Cisco.IOS.Monster.Collection.2008