Clear VTY Lines

Sometimes a switch/router won't let you connect to it. Coming back as telnet/shh connection refused. If the hardware is otherwise functioning correctly, its likely that your VTY lines are full.
This is how you can:
see all sessions / see active sessions / kill sessions

# sh users all
# sh users
# clear line

Get your GNS3 project fix

Here's a link to a great site from my friend Rene Molenaar:
GNS3Vault

Description from the site:

* Cool Scenarios to get the maximum out of your networking experience ;)
* Downloadable topologies that you can use right away with the GNS3 software.
* Different levels of difficulty, there's something for everyone...novice, intermediate and expert!
* The forum where you can discuss about all the labs.
* It's possible to review labs.
* You can share your labs with others.

AND Yes, all for free ;)