How Firewalls Work
Whether you use your PC on a large network for a business or use it for surfing the Internet at home, the same security issues and concerns apply regardless of the size of the network you use. This is why it is a good idea to employ a firewall to provide a protective barrier between your network and the Internet.
How Firewall Software Works
A firewall works similar to an antivirus program by filtering information that comes in from the Internet and into the company network or the network that you have installed in your home. A firewall is capable of protecting a large number of PCs or a single PC.
- Large Network: On a large network, each PC has what is called a network card that connects a group of PCs together. The PCs access the Internet via several different lines known as T1 or T3 lines. The firewall is placed on each of the lines that are connecting to the Internet and can be configured to create rules for information that comes into the network from the Internet.
For example, the IT administrator can set up firewall rules that control how PC users access websites and what kind of information is allowed to be transmitted from the network to the website. The rules can be customized by IP addresses, specific words, domain names, and other protocols that set rules for how the PC user and the server will communicate.
- Home Network: Depending upon your PCs operating system the firewall if often built-in. If your operating system does not include a firewall, you can install firewall software which provides a barrier between your home network and the Internet.
There are also hardware firewalls that offer good security and can be configured through your home router that connects to the cable modem for Internet connectivity. Like a firewall on a large network, you can configure the firewall with certain rules and filters.
Although you may have a good antivirus program, it is a good idea to install and configure a firewall for added protection because there are countless ways that online criminals can attack your computer. In addition to viruses, trojans, worms, spyware, and other related malicious software that affects your PC, online criminals can crash your server, run your PC programs, send information to a different router and make it appear like it came from a trusted source, and send unsolicited junk email to your contact list using your server, to name a few things.
Most firewall software has certain rules set by default which is usually sufficient for home users; however, on larger networks it is best to have an experienced IT administrator configure the firewall according the needs of the organization. Also, it is important to keep in mind that firewall protection should not be substituted for an antivirus program. The two programs should work together to provide as much protection for your PC and network as possible.