Firewalls

Connecting to the Internet without a firewall is like leaving the keys in your car with the engine running and the doors unlocked while you run into the store. Although you may be able to get in and out before anyone notices, someone may take advantage of the opportunity. On the Internet, hackers use malicious code—such as viruses, worms, and Trojan horses—to try to find unprotected computers. A firewall can help protect your computer against these and other security attacks.

So what can a hacker do? It depends on the nature of the attack. While some attacks are just nuisances that may play simple pranks, others are created with malicious intent. These more severe strains may attempt to delete information from your computer, crash it, or even steal personal information, such as passwords or credit card numbers. Some hackers enjoy nothing better than breaking into vulnerable computers. Viruses, worms, and Trojan horses are scary. Fortunately, you can reduce your risk of infection by using a firewall.

On This Page

How do I choose a firewall?

A firewall works by examining information coming from and going to the Internet. It identifies and ignores information that comes from a dangerous location or seems suspicious. If you set up your firewall properly, hackers searching for vulnerable computers can't detect your computer.

There are three basic types of firewalls available today. The first step in choosing a firewall is to determine which one is best for you. Your options include:

Software firewalls
Hardware routers
Wireless routers

To get started, answer these questions:

How many computers will be using the firewall?
What operating system are you using? (This might be a version of Microsoft Windows®, Apple Macintosh, or Linux.)

That's it. You are now ready to start thinking about what type of firewall you would like to use. There are several options, each with its own pros and cons.

Windows Firewall (Windows XP Service Pack 2)

If you are using Window XP Service Pack 2 (SP2), the most updated version of Windows XP, you have a firewall built-in and turned on by default. To learn more about the Windows Firewall that comes with Windows XP SP2, read Understanding Windows Firewall.

Tip: If you haven't downloaded Service Pack 2, it is included on the CD.

If you are using Windows XP and you choose not to download Service Pack 2, you'll still have access to the Internet Connection Firewall (ICF) that's built into Windows XP, but you'll need to turn it on. For more information see Use the Internet Connection Firewall.

Note: The Windows Firewall and the Internet Connection Firewall are not available as a stand-alone package. They are also not available for other operating systems (for example, Apple Macintosh or Linux) or for versions of Windows other than Windows XP.

Software firewalls

Software firewalls are a good choice for single computers, and they work well with Windows 98, Windows ME, and Windows 2000. (Windows XP has a built-in firewall, so an additional firewall is not necessary.)

Software firewalls are available from other software companies. For special offers on antivirus and firewall packages, visit the Microsoft Security software: Downloads and trials page.

Pros	Cons
Does not require additional hardware.	Additional cost: Most software firewalls cost money.
Does not require additional computer wiring.	Installation and configuration may be required to get started.
A good option for single computers.	One copy is typically required for each computer.

Hardware routers

Hardware routers are a good choice for home networks that will be connected to the Internet.

Pros	Cons
Hardware routers usually have at least four network ports to connect other computers together.	Requires wiring, which can clutter your desktop area.
Hardware routers provide firewall protection for multiple computers.

Wireless routers

If you have or are planning to use a wireless network, you will need a wireless access point router. Only a few wireless routers come equipped with a built-in firewall, so you may need to purchase a firewall separately.

Pros	Cons
Wireless routers allow you to connect computers, portable computers, personal desk assistants, and printers without using wiring.	Wireless devices broadcast information using radio signals that can be intercepted by someone outside of your home (with the right equipment).
Wireless routers are excellent for connecting notebook computers to the Internet and networks.	Using a wireless router requires you to use a wireless adapter in any computer that connects to it. Therefore, you may have to pay for extra equipment.
	Not all wireless routers come equipped with a built-in firewall, so you may have to purchase one separately.

Next step: Start using a firewall today

Connecting to the Internet can create dangers for the unaware computer user. Using a firewall can help reduce your risk. Installing a firewall is just the first step toward safer surfing online. You can continue to improve your computer's security by keeping your software up to date and maintaining a current antivirus software subscription.