Search

The Definitive Guide to Building Firewalls with Linux As the security challenges facing Linux system and network administrators have grown, the security tools and techniques available to them have improved dramatically. In Linux® Firewalls, Fourth Edition, long-time Linux security expert Steve Suehring has revamped his definitive Linux firewall guide to cover the important advances in Linux security. An indispensable working resource for every Linux administrator concerned with security, this guide presents comprehensive coverage of both iptables and nftables. Building on the solid networking and firewalling foundation in previous editions, it also adds coverage of modern tools and techniques for detecting exploits and intrusions, and much more. Distribution neutral throughout, this edition is fully updated for today's Linux kernels, and includes current code examples and support scripts for Red Hat/Fedora, Ubuntu, and Debian implementations. If you're a Linux professional, it will help you establish an understanding of security for any Linux system, and for networks of all sizes, from home to enterprise. Inside, you'll find just what you need to Install, configure, and update a Linux firewall running either iptables or nftables Migrate to nftables, or take advantage of the latest iptables enhancements Manage complex multiple firewall configurations Create, debug, and optimize firewall rules Use Samhain and other tools to protect filesystem integrity, monitor networks, and detect intrusions Harden systems against port scanning and other attacks Uncover exploits such as rootkits and backdoors with chkrootkit

System administrators need to stay ahead of new security vulnerabilities that leave their networks exposed every day. A firewall and an intrusion detection systems (IDS) are two important weapons in that fight, enabling you to proactively deny access and monitor network traffic for signs of an attack.Linux Firewalls discusses the technical details of the iptables firewall and the Netfilter framework that are built into the Linux kernel, and it explains how they provide strong filtering, Network Address Translation (NAT), state tracking, and application layer inspection capabilities that rival many commercial tools. You'll learn how to deploy iptables as an IDS with psad and fwsnort and how to build a strong, passive authentication layer around iptables with fwknop.Concrete examples illustrate concepts such as firewall log analysis and policies, passive network authentication and authorization, exploit packet traces, Snort ruleset emulation, and more with coverage of these topics:–Passive network authentication and OS fingerprinting–iptables log analysis and policies–Application layer attack detection with the iptables string match extension–Building an iptables ruleset that emulates a Snort ruleset–Port knocking vs. Single Packet Authorization (SPA)–Tools for visualizing iptables logsPerl and C code snippets offer practical examples that will help you to maximize your deployment of Linux firewalls. If you're responsible for keeping a network secure, you'll find Linux Firewalls invaluable in your attempt to understand attacks and use iptables—along with psad and fwsnort—to detect and even prevent compromises.

The author draws on his experience to offer the reader valuable advice on the best practices. Providing only necessary theoretical background, the book takes a practical approach, presenting case studies and plenty of illustrative examples. This book is aimed at Linux Network administrators!--[if!supportAnnotations]-- with some understanding of Linux security threats and issues, or any one interested in securing their systems behind a firewall. Basic knowledge of Linux is presumed but other than that this book shows you how to do the rest, from configuring your system to dealing with security breaches.