Thinking of sitting a Cisco networking certification? If so then I definitely recommend you check out the PacketLife.net website. This site offers a wealth of useful information relating to Cisco and networking in general with a wiki, forum, various downloadable cheat sheets and Cisco IOS interior routing protocols wall poster.
Of course when studying to sit a Cisco certification it can be hard for many to get hands on time with the actual Cisco networking hardware which is where Stretch at PacketLife.net generously offers access to an online lab environment which allows you to get the much needed hands on time. It is very organised and has a schedule on which you can book some time in the lab.
Highly useful I think you’ll agree and full credit to Stretch at PacketLife.net for providing the online community lab environment.