Firewalls

Home

Firewalls

Home

Firewalls

What is a firewall?

When your computer is connected to the Internet, it receives traffic from a wide range of sources, most of it benign. Your instant messaging client alerts you that a friend has signed on; your mail client finds new mail waiting for you and downloads it; a weather site refreshes its rainfall map by telling your web browser to reload a page.

All of this traffic is handled invisibly by your computer, which is listening to a large number of "ports." A port is a specific connection point through which applications on your computer connect to the Internet. And a hacker only needs one open port through which to mount an attack.

Are There Different Types of Firewalls?

There are two main types of firewalls: hardware and software.

A hardware firewall is an external box sitting between the Internet and your computer. For home environments firewall functions are usually integrated in broadband routers, which allow you to connect to the Internet and share the connection with other computers too.

Why do I need a firewall?

Without a firewall, your computer is operating under an "open door" policy. Bank account information. Passwords. Credit card numbers. Documents and photos that you don't want to share with the world. They are all available to anyone with bad intentions and basic computer skills.