Book excerpt: 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.