Linux Advanced Routing and Traffic Control HOWTO
Gregory Maxwell & Remco Mook & Martijn Oosterhout & Paul Schroeder & Jasper Spaans & Bert Hubert
The the Complete Metasploit Guide
Sagar Rahalkar & Nipun Jaswal
CyBOK
Awais Rashid & Howard Chivers & George Danezis & Emil Lupu & Andrew Martin
Mastering Linux Network Administration
Jay LaCroix
SSH Mastery: OpenSSH, PuTTY, Tunnels and Keys
Michael W Lucas