Linux Firewalls: Attack Detection and Response with iptables, psad, and fwsnort
- 6h 6m
- Michael Rash
- No Starch Press
- 2007
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 logs
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 and fwsnort—to detect and even prevent compromises.
About the Author
Michael Rash is a Security Architect on the Dragon Intrusion Detection System with Enterasys Networks, Inc., and is a frequent contributor to open source projects. As the creator of psad, fwknop, and fwsnort, Rash is an expert on firewalls, IDSs, OS fingerprinting, and the Snort rules language. He is co-author of the book Snort 2.1 Intrusion Detection, lead-author and technical editor of the book Intrusion Prevention and Active Response, and has written security articles for Linux Journal, SysAdmin, and ;login:.
In this Book
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Care and Feeding of iptables
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Network Layer Attacks and Defense
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Transport Layer Attacks and Defense
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Application Layer Attacks and Defense
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Introducing PSAD: The Port Scan Attack Detector
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psad Operations: Detecting Suspicious Traffic
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Advanced psad Topics: From Signature Matching to OS Fingerprinting
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Active Response with psad
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Translating Snort Rules Into Iptables Rules
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Deploying fwsnort
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Combining psad and fwsnort
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Port Knocking vs. Single Packet Authorization
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Introducing fwknop
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Visualizing iptables Logs
