First block everything, then let all you want through. The micro-course presents advanced network firewall mechanisms managed by the iptables command. The information contained enables creating a firewall beginning with basic procedures, using standard rules of blocking and finishing with stateful procedures and logging information. Keywords: iptables, rcSuSEfirewall2, conntrack
Firewalls, Network Address Translation (NAT), network logging and accounting are all provided by Linux's Netfilter system, also known by the name of the command used to administer it, iptables. The iptables interface is the most sophisticated ever offered onLinux and makes Linux an extremely flexible system for any kind of network filtering you might do. Large sets of filtering rules can be grouped in ways that makes it easy to test them and turn them on and off.Do you watch for all types of ICMP traffic--some of them quite dangerous? Can you take advantage of stateful filtering to simplify the management of TCP connections? Would you like to track how much traffic of various types you get?This pocket reference will help you at those critical moments when someone asks you to open or close a port in a hurry, either to enable some important traffic or to block an attack. The book will keep the subtle syntax straight and help you remember all the values you have to enter in order to be as secure as possible. The book has an introductory section that describes applications,followed by a reference/encyclopaedic section with all the matches and targets arranged alphabetically.
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.
* Everything readers need to construct firewalls that protect computer networks from attacks and intrusions * Covers the migration from ipchains and how to mange iptable log files * Reviews the customization of firewalls, the Red Hat firewall tool, the firewall setup, and advanced firewall features * Includes numerous examples of firewalls and firewall administration techniques that work on Red Hat Linux systems * Explains how to cost-justify, implement, test, and operate packet filtering firewalls constructed using Red Hat Linux RED HAT(r) PRESS(TM) Linux Solutions from the Experts at Red Hat Red Hat-the world's leading Linux company-presents a series of unrivaled guides that are reviewed and approved by the experts at Red Hat. Each book is packed with invaluable tips and techniques that are ideal for everyone from beginning to advanced network and systems professionals, as well as home and small businesses.
This edition offers both new and thoroughly updated hacks for Linux, Windows, OpenBSD, and Mac OS X servers that not only enable readers to secure TCP/IP-based services, but helps them implement a good deal of clever host-based security techniques as well.
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
*Imparts good security doctrine, methodology, and strategies *Each application-focused chapter will be able to be used as a stand-alone HOW-TO for that particular application. *Offers users a selection of resources (websites, mailing lists, and books) to further their knowledge.
LPIC-2 Cert Guide (201-400 and 202-400 Exams) is a best-of-breed exam study guide. Expert Linux/Unix instructor William “Bo” Rothwell shares preparation hints and test-taking tips, helping you identify areas of weakness and improve both your conceptual knowledge and hands-on skills. Material is presented in a concise manner, focusing on increasing your understanding and retention of exam topics. The book presents you with an organized test preparation routine through the use of proven series elements and techniques. Exam topic lists make referencing easy. Chapter-ending Exam Preparation Tasks help you drill on key concepts you must know thoroughly. Review questions help you assess your knowledge, and a final preparation chapter guides you through tools and resources to help you craft your final study plan. You get access to the powerful Pearson IT Certification Practice Test engine, complete with hundreds of exam-realistic questions. The assessment engine offers you a wealth of customization options and reporting features, laying out a complete assessment of your knowledge to help you focus your study where it is needed most. Well-regarded for its level of detail, assessment features, and challenging review questions and exercises, this study guide helps you master the concepts and techniques that will allow you to succeed on the exam the first time. The study guide helps you master all the topics on both LPIC-2 exams, including: Capacity planning Managing the kernel Managing system startup Managing filesystems and devices Administering advanced storage devices Configuring the network Performing system maintenance Administering Domain Name Server (DNS) Configuring web services Administering file sharing Managing network clients Administering e-mail services Administering system security Learn, prepare, and practice for LPIC-2 201-400 and 202-400 exam success with this Cert Guide from Pearson IT Certification, a leader in IT Certification. Master LPIC-2 Exam 201-400 and 202-400 exam topics Assess your knowledge with chapter-ending quizzes Review key concepts with exam preparation tasks Practice with realistic exam questions
What an amazing world we live in! Almost anything you can imaginecan be researched, compared, admired, studied, and in many cases,bought, with the click of a mouse. The Internet has changed ourlives, putting a world of opportunity before us. Unfortunately, ithas also put a world of opportunity into the hands of those whosemotives are less than honorable. A firewall, a piece of software orhardware that erects a barrier between your computer and those whomight like to invade it, is one solution. If you’ve been using the Internet for any length of time,you’ve probably received some unsavory and unsolicitede-mail. If you run a business, you may be worried about thesecurity of your data and your customers’ privacy. At home,you want to protect your personal information from identity thievesand other shady characters. Firewalls ForDummies® will give you the lowdown onfirewalls, then guide you through choosing, installing, andconfiguring one for your personal or bus iness network. Firewalls For Dummies® helps youunderstand what firewalls are, how they operate on different typesof networks, what they can and can’t do, and how to pick agood one (it’s easier than identifying that perfect melon inthe supermarket.) You’ll find out about Developing security policies Establishing rules for simple protocols Detecting and responding to system intrusions Setting up firewalls for SOHO or personal use Creating demilitarized zones Using Windows or Linux as a firewall Configuring ZoneAlarm, BlackICE, and Norton personalfirewalls Installing and using ISA server and FireWall-1 With the handy tips and hints this book provides, you’llfind that firewalls are nothing to fear – that is,unless you’re a cyber-crook! You’ll soon be able tokeep your data safer, protect your family’s privacy, andprobably sleep better, too.
