Here are some articles I wrote in the past, some of them are outdated but feel free to use, correct and transform them.
These articles are written in both English and French
Inside a PIX Firewall
Introduction to policy routing
Here are some articles I wrote in the past, some of them are outdated but feel free to use, correct and transform them.
Introduction to policy routing
Using POP3 protocol manually
Introduction to some network medias
Non-Security risks
Introduction to UNIX commands