There are several books that provide excellent general knowledge about firewalls. They include: Cheswick, B., & Bellovin, S. (1994). Firewalls and Internet security:
Repelling the wily hacker. ISBN 0-201-63357-4. Addison Wesley.
Garfinkel, S., & Spafford, G. (1996). Practical Internet & Unix security. ISBN 1-56592-148-8. O Reilly Books.
Zwicky, E.D., Cooper, S., & Chapman, D.B. (2000). Building Internet firewalls (2 nd ed.). ISBN1-56592-871-7. O Reilly Books.
Additional related references are:
Comer, D., & Stevens, D. (1992). Internetworking with TCP/IP (vols. I, II, III). ISBN 0-13-468505-9 (I), 0-13-472242-6 (II), 0-13-474222-2 (III). Prentice-Hall. (A detailed discussion on the architecture and implementation of the Internet and its protocols. Volume I on principles, protocols and architecture is readable by everyone. Volume 2 (on design, implementation and internals) is more technical. Volume 3 covers client-server computing.)
Curry, D. (1992). Unix system security ” A guide for users and system administrators. ISBN 0-201-56327-4. Addison Wesley.
Firewalls Mailing List (Curtin, 2000) http://lists.gnac.net/firewalls. The Internet firewalls mailing list is a forum for firewall administrators and implementers. To subscribe to Firewalls, send subscribe firewalls in the body of a message (not in the Subject line) to majordomo@lists.gnac.net
http://sunsite.unc.edu/LDP/HOWTO/Firewall-HOWTO.html. Describes exactly what is needed to build a firewall, particularly using Linux. Firewall Toolkit (FWTK) and Firewall Papers: ftp://ftp.tis.com/pub/firewalls/
Marcus Ranum s firewall related publications : http://www.ranum.com/pubs/
ftp://ftp.research.att.com/dist/internet_security/
Texas A&M University security tools: http://www.net.tamu.edu/ftp/security/TAMU/
COAST Project Internet Firewalls page: http://www.cs.purdue.edu/ coast /firewalls/