In the past, firewalls were reserved for large company networks. Until recently, most home Internet users were still on standard 56K dial up modems, which were too slow to be of much use to hacker groups. With the introduction of inexpensive high speed media such as cable modems, digital subscriber lines (DSL), and satellite modems, more home users are experiencing the effects of hacker activity on their personal computers.
Users now need something to protect their computers from malicious attacks from outsiders. This is where a firewall comes into play. A firewall pretty much acts like a gatekeeper; it lets in the people who are supposed to get in, and prevents anyone else from passing. Webopedia's definition of a firewall is as follows:
(fir´wâl) (n.) A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
Hardware firewalls are separate pieces of equipment specially made to keep unwanted visitors out. Common brands in this field are Cisco, Enterasys, and 3com . They are the most effective form of firewall that can be put into place, but their higher price keeps them out of reach for most users. A true hardware firewall runs in the hundreds to thousands of dollars, as opposed to software firewall programs that can be obtained for under a hundred dollars.
For most users, software firewalls are sufficient to protect them from most hacker threats on the Internet. Network routers and switches have limited firewall functions built into them, but these devices only offer the most basic features that a true hardware firewall has. For more information on these devices and the limits of what they can and can't do, refer to the manual for your device or the manufacturer's website--features vary. If you don't have network equipment but are considering purchasing some, consult our Home Network section.
There are many different manufacturers of software firewalls, and some firewalls may already exist in places that you are not aware. For example, if you currently have Windows XP on your computer, you have a firewall already built into Windows itself. Both the firewall and security settings may be accessed from the Control Panel. To see screen shots click here.
To learn more about the built-in firewall in Windows, visit Understanding Windows XP Firewalls
If you do not have Windows XP and need a firewall, there is an absolutely free software firewall called ZoneAlarm. It is one of the better ones out there, and has had very good reviews.
For a reasonable $69.95 you can get Norton Internet Security, which comes with Norton Antivirus. You can learn more about Norton Antivirus from our Antivirus Software page.