LINUX FIREWALLS

by Michael Rash
(Attack Detection and Response with iptables, psad, and fwsnort)

This book assumes some familiarity with TCP/IP networking concepts and Linux system administration. Knowledge of the Open System Interconnection (OSI) Reference Model and the main network and transport layer protocols (IPv4, ICMP, TCP, and UDP), as well as some knowledge of the DNS and HTTP application protocols would be most helpful. Although frequent references are made to the various layers of the OSI Reference Model, the network, transport, and application layers (3, 4, and 7, respectively) receive the vast majority of the discussion.