Building Linux and OpenBSD Firewalls , by Wes Sonnenreich and Tom Yates. John Wiley & Sons, 2000.
SSH: The Secure Shell: The Definitive Guide , by Daniel J. Barrett and Richard E. Silverman. O'Reilly, 2001.
Bastille Linux. (http://www.bastille-linux.org)
Linux capabilities. (http://ftp.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.4/capfaq-0.2.txt)
Excellent site on log analysis. (http://www.loganalysis.org)
Linux Kernel Security. (http://www.lids.org)
DNS and BIND , by Paul Albitz and Cricket Liu. O'Reilly, 2001.
Apache: The Definitive Guide , by Ben Laurie and Peter Laurie. O'Reilly, 2002.
Unix in a Nutshell , by Arnold Robbins. O'Reilly, 1999.
Unix CD Bookshelf , various authors. O'Reilly, 2000.
Introduction to Linux Capabilities and ACLs , by Jeremy Rauch. (http://www.securityfocus.com/infocus/1400)
