The following titles are some excellent supporting references for the more technical aspects of this book:
Building Internet Firewalls, 2nd Edition; Elizabeth D. Zwicky, Simon Cooper, and D. Brent Chapman (O'Reilly, 2000)
Computer Networks, 4th Edition; Andrew S. Tannenbaum (Prentice Hall PTR, 2002)
Firewalls and Internet Security: Repelling the Wily Hacker, 2nd Edition; William R. Cheswick, Steven M. Bellovin, and Aviel D. Rubin (Addison-Wesley Professional, 2003)
Linux System Security, 2nd Edition; Scott Mann and Ellen L. Mitchell (Pearson Education, 2002)
Programming Perl, 3rd Edition; Larry Wall, Tom Christiansen, and Jon Orwant (O'Reilly, 2000)
The Tao of Network Security Monitoring: Beyond Intrusion Detection; Richard Bejtlich ...