The purpose of this chapter is to introduce the reader to firewalls and the built-in Mac OS X tools. Because firewall configuration varies from network to network, your ruleset may require only a handful of entries, whereas another may encompass hundreds. Additional information on firewalls and building firewall rulesets can be found in the following resources:
"BSD Firewalls: IPFW," O'Reilly ONLamp.com, http://www.onlamp.com/pub/a/bsd/2001/04/25/FreeBSD_Basics.html?page=1.
"BSD Firewalls: IPFW Rulesets," O'Reilly ONLamp.com, http://www.onlamp.com/pub/a/bsd/2001/05/09/FreeBSD_Basics.html.
"IPFW Logging," O'Reilly ONLamp.com, http://www.onlamp.com/pub/a/bsd/2001/06/21/FreeBSD_Basics.html.
"Setting Up Firewall Rules on Mac OS X 10.2," D. Cote, http://www3.sympatico.ca/dccote/firewall.html.
Building Linux and OpenBSD Firewalls , Wes Sonnenreich and Tom Yates, ISBN 0471353663.
"Protecting Your Private Network Using FreeBSD," Peter Brezny, http://www.bsdtoday.com/2000/December/Features359.html.
"IPFW How To," http://www.defcon1.org/html/NATD-config/firewall-setup/ipfw-1.html.
"Security," FreeBSD Handbook , Gary Palmer and Alex Nash, http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/firewalls.html.