Linux Firewalls / Edition 2

Linux Firewalls / Edition 2

5.0 1
by Robert L. Ziegler, Carl Constaintine, Carl B. Constaintine
     
 

ISBN-10: 0735710996

ISBN-13: 9780735710993

Pub. Date: 10/24/2001

Publisher: Pearson Education

An Internet-connected Linux machine is in a high-risk situation. This book details security steps that a home or small-to-mid-size, non-enterprise business might take to protect itself from potential remote attackers. As with the first edition, this book will provide a description of the need for security measures and solutions built upon the most up-to-date

Overview

An Internet-connected Linux machine is in a high-risk situation. This book details security steps that a home or small-to-mid-size, non-enterprise business might take to protect itself from potential remote attackers. As with the first edition, this book will provide a description of the need for security measures and solutions built upon the most up-to-date technology available. The content for the Second Edition has been updated to cover the 2.4 kernel, and additional chapters on VPNs, SSH, and Tripwires have been added.

Product Details

ISBN-13:
9780735710993
Publisher:
Pearson Education
Publication date:
10/24/2001
Series:
Landmark Series
Edition description:
Older Edition
Pages:
562
Product dimensions:
7.02(w) x 8.96(h) x 1.24(d)

Table of Contents

IPacket-Filtering and Basic Security Measures1
1Preliminary Concepts Underlying Packet-Filtering Firewalls3
The TCP/IP Reference Networking Model5
IP Addresses8
Routing: Getting a Packet from Here to There12
Service Ports: The Door to the Programs on Your System12
Packets: IP Network Messages15
Summary26
2Packet-Filtering Concepts27
A Packet-Filtering Firewall30
Choosing a Default Packet-Filtering Policy32
Rejecting Versus Denying a Packet34
Filtering Incoming Packets35
Filtering Outgoing Packets52
Private versus Public Network Services55
Summary79
3ptables: The Linux Firewall Administration Program81
Differences Between IPFW and Netfilter Firewall Mechanisms81
iptables Features85
iptables Syntax90
Summary110
4Building and Installing a Standalone Firewall111
iptables: The Linux Firewall Administration Program112
Initializing the Firewall114
Protecting Services on Assigned Unprivileged Ports125
Enabling Basic, Required Internet Services130
Enabling Common TCP Services137
Enabling Common UDP Services165
Filtering ICMP Control and Status Messages171
Logging Dropped Incoming Packets174
Logging Dropped Outgoing Packets176
Denying Access to Problem Sites Up Front176
Installing the Firewall177
Summary179
IIAdvanced Issues, Multiple Firewalls, and Perimeter Networks181
5Firewall Optimization183
Rule Organization183
User-Defined Chains187
Optimized Example190
What Did Optimization Buy?209
Summary212
6Packet Forwarding213
The Limitations of a Standalone Firewall214
Basic Gateway Firewall Setups215
LAN Security Issues217
Configuration Options for a Trusted Home LAN218
Configuration Options for a Larger or Less Trusted LAN222
A Formal Screened-Subnet Firewall230
Converting the Gateway from Local Services to Forwarding262
Summary263
7NAT--Network Address Translation265
The Conceptual Background of NAT265
iptables NAT Semantics270
Examples of SNAT and Private LANs275
Examples of DNAT, LANs, and Proxies277
Summary283
8Debugging the Firewall Rules285
General Firewall-Development Tips286
Listing the Firewall Rules288
Checking the Input, Output, and Forwarding Rules298
Checking for Open Ports304
Debugging SSH: A Real-Life Example308
Summary310
IIISystem-Level Security and Monitoring311
9Verifying That the System Is Running as You Expect313
Checking the Network Interfaces with ifconfig313
Checking the Network Connection with ping315
Checking Network Processes with netstat316
Checking a Process Bound to a Particular Port with fuser317
Checking All Processes with ps -ax318
Interpreting the System Logs320
Summary330
10Issues at the UNIX System Administration Level331
Authentication: Verifying Identity331
Authorization: Defining Access Rights to Identities334
Server-Specific Configuration341
SOCKS: An Application-Level Proxy Firewall379
Miscellaneous System Accounts in /etc/passwd, /etc/shadow, and /etc/group380
Setting Your PATHVariable382
/etc/issue.net383
Remote Logging384
Keeping Current with Software Upgrades384
Summary385
11Secure Shell (SSH)387
Installing SSH390
Generating SSH Keys392
Using SSH394
Customizing Your SSH Configuration398
Secure Copy (scp)404
Summary405
12Tripwire407
Tripwire Overview407
Installing Tripwire408
Looking at How Tripwire Works410
Configuring Tripwire415
Using Tripwire421
Tripwire Tips and Tricks430
Summary432
13Intrusion Detection and Incident Reporting Software433
Intrusion-Detection Software434
Symptoms Suggesting That the System Might Be Compromised437
What to Do if Your System Is Compromised441
Incident Reporting442
Summary448
IVAppendixes449
ASecurity Resources451
Security Information Sources451
Software Collections452
Security Tools453
Firewall Tools454
Reference Papers and FAQs455
General Web Sites458
Books459
BFirewall Examples and Support Scripts461
iptables Firewall for a Standalone System from Chapter 4462
Optimized iptables Firewall from Chapter 5478
iptables Firewall for a Choke Firewall from Chapter 6493
Special Purpose Support Scripts504
DHCP and pump: Firewall Support with a Dynamic IP Address and Name Servers508
CVPN511
Overview of Virtual Private Networks (VPN)511
Types ofVPN512
VPN Protocols513
Linux and VPN Products518
VPN Configurations520
Connecting Networks521
VPN and Firewalls522
DGlossary525
Index537

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Linux Firewalls 5 out of 5 based on 0 ratings. 1 reviews.
Guest More than 1 year ago
This book makes the process of designing, understanding, and monitoring a linux-based firewall very easy. Anyone interested in building an inexpensive but very powerful, configurable firewall should STRONGLY consider this book, as it covers practically every aspect of firewall construction and configuration.