Use iptables to detect and prevent network-based attacks
System administrators need to stay ahead of new security vulnerabilities that
leave their networks exposed every day. A firewall and an intrusion detection
system (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:
• Application layer attack detection with the iptables string match extension
and fwsnort
• Building an iptables ruleset that emulates a Snort ruleset
• Port knocking vs. Single Packet Authorization (SPA)
• Tools for visualizing iptables logs
• Passive OS fingerprinting with iptables
Perl 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 andfwsnort-to detect and even prevent compromises.
Foreword by Richard Bejtlich
Introduction
Chapter 1: Care and Feeding of iptables
Chapter 2: Network Layer Attacks and Defense
Chapter 3: Transport Layer Attacks and Defense
Chapter 4: Application Layer Attacks and Defense
Chapter 5: Introducing psad: The Port Scan Attack Detector
Chapter 6: psad Operations: Detecting Suspicious Traffic
Chapter 7: Advanced psad Topics: From Signature Matching to OS Fingerprinting
Chapter 8: Active Response with psad
Chapter 9: Translating Snort Rules into iptables Rules
Chapter 10: Deploying Fwsnort
Chapter 11: Combining psad and Fwsnort
Chapter 12: Port-Knocking vs. Single Packet Authorization
Chapter 13: Introducing fwknop
Chapter 14: Visualizing iptables Logs
Appendix A: Attack Spoofing
Appendix B: A Complete fwsnort Script
Product Details
* ISBN: 1593271417
* ISBN-13: 9781593271411
* Format: Paperback, 308pp
* Publisher: No Starch Press San Francisco, CA
* Pub. Date: July 2007
