:santagrin: This book is suggested by Neil A. Smyth

The purpose of this book is to first provide the reader with a deep understanding of TCP/IP layers, protocols and packet formats and subsequently provide a step-by-step outline of iptables and Netfilter configuration to implement a secure Linux environment. The book also covers topics such as Network Address Translation (NAT) and both stateful and stateless packet filtering including a number of example scripts to jump-start the firewall configuration process.

On completion of this book the reader will have a clear understanding of network protocols, packet formats, firewall configuration, packet filtering concepts and practical experience using the iptables and Netfilter frameworks.

Intended Audience:

This book is intended for experienced and new Linux administrators alike, with some previous knowledge about Linux/Unix, shell scripting, as well as how to compile a kernel, and some simple knowledge about the kernel internals. It's also a recommended reading for anyone just looking to get a better understanding of network protocols and Linux firewalls.