Linux Firewalls
Michael Rash
Securing DevOps
Julien Vehent
Cyber Security and Network Security
Sabyasachi Pramanik & Debabrata Samanta & M. Vinay & Abhijit Guha
Cloud Attack Vectors
Morey J. Haber & Brian Chappell & Christopher Hills
SSH Mastery: OpenSSH, PuTTY, Tunnels and Keys
Michael W Lucas