Hydra is a tool that makes cracking protocols such as ssh, ftp and telnet relatively easy. In my example, I will be cracking SSH using Hyrda 5.9.1 on Ubuntu 10.10 64 bit (***Update for Ubuntu 12.04 - Replace all references of Hydre 5.9.1 with Hyrda 7.3, which can be downloaded here). Although this example uses Ubuntu, these commands should work on any Debian based system such as Debian and Linux Mint.