Linux Advanced Routing and Traffic Control HOWTO
Gregory Maxwell & Remco Mook & Martijn Oosterhout & Paul Schroeder & Jasper Spaans & Bert Hubert
Designing and Implementing Linux Firewalls with QoS Using Netfilter, ...
Lucian Gheorghe
CyBOK
Awais Rashid & Howard Chivers & George Danezis & Emil Lupu & Andrew Martin
Mastering Linux Network Administration
Jay LaCroix
Bash Idioms: Write Powerful, Flexible, Readable Shell Scripts
Carl Albing & J P Vossen