Use the native IPsec stack to connect multiple networks over the internet.
Trace packets as they pass through the iptables firewall.
Determine SSL cipher suites supported by the web-server using OpenSSL.
Log every executed command to syslog.
I will show you how to generate a random password using the OpenSSL utility, standard command-line utilities, Password Generator (pwgen), and Automated Password Generator (APG).
A week ago I wrote about a couple of interesting applications that can crack passwords, but they were not as fast as I thought. After investigating this topic further, I ended up using a community-enhanced version of John the Ripper.
Sometimes it a good idea to check or just store contents of the virtual console terminal (/dev/vcs[1-63] device).
Display established TCP connections inside the terminal.