Rating: 

This second edition explains in great detail about firewalls, both in building them (and the software and hardware you can use) and maintaining them. It also discusses the different types of firewalls available, which services you want to protect (World Wide Web, electronic mail and netnews,
FTP, telnet, teleconferencing, for example).

The book is timely enough to discuss the 'break-ins' of several well-known web sites earlier this year, thus pointing out one need for the use of firewalls. While I learned quite a bit of good information, the second section (Building Firewalls) is where I personally learned the most. The chapters in this section discuss topics like packet filtering, firewall >architectures and design, proxy systems and bastion hosts.

The book also talks about reasons for having (or not having) a firewall,security issues and near the end of the book, what to do if the site you're
protecting with a firewall does get broken into.

An informative, well-put together book that can be used as a reference and >in some sections, a tutorial as well.