Internet Firewalls and Network Security succeeds precisely because of its restricted focus: half of this book is devoted to firewalls and packet filters. After a comprehensive introduction to the architecture and theory of firewalls, the guide documents several commercial and noncommercial packages, including a shareware product included on the bundled CD-ROM.

One of the book's highlights is a fine chapter on defining a network policy. Coauthor Chris Hare is a contributor to SysAdmin magazine, and it shows. This section feels like it was written for real-world network administrators, whether beginning or experienced. There are some weaker points, including an introduction to TCP/IP and Unix basics with too many details for the beginner and too few for the expert. But these flaws are more than offset by the depth of information you'll find on the book's core subjects.