by Carl Constantine
It wasn't that many years ago that people rarely locked the doors to their homes. There wasn't a need. If you lived in rural parts and weren't home, often the milkman would walk right into your home and put it in the fridge.
Now, however, every door, window, or access point to your house is locked tight. And in some areas, people put bars on the windows to make it more difficult for would-be criminals to gain access to their home. And where milk is still being delivered ... well, it's most likely left on your doorstep instead of staying cold in the fridge.
The same is true with the Internet. Not long ago, if your computer had access to the Internet, you roamed around freely without peeking around each corner first. At the time, dedicated Internet access was expensive, and only the major educational and government institutions could afford it. Still fewer people even knew what the Internet was, never mind the need for a secure system.
Today's world of inexpensive high-speed access via cable modems or various incarnations of DSL technology has changed the landscape. Almost everyone knows about or uses the Internet on a daily basis. In today's world, malicious crackers attempt to break into systems to destroy data, steal information, or plant various computer viruses. While not every computer hacker is a cyber criminal, the threat is very real, and everything you do to discourage access to your computer or make it difficult to gain access to your computer goes a long way toward keeping your data safe.
Inexpensive high-speed Internet access has allowed the average home computer user to set up a small dedicated Internet server to share files with friends, send e-mail, and more. However, computer security is an afterthought. Many people think they don't need to worry about their system being compromised. "I have nothing of value," they rationalize. That is the worst thing anyone can possibly say.
Admittedly, I myself took a passive role in securing my system, shrugging off the idea that anyone would want to gain access to my system. However, after several discussions about Internet security and firewalls on our Linux Users Group mail list, I decided to research things further and set up my own firewall in the process for the experience.
Securing your home computer or home network requires that you understand a little about your setup. Important considerations include the kind of network connection you have (cable, DSL, or dedicated T1-T3), the approximate amount of network traffic that goes through your system, any extra hardware that can be used as a dedicated firewall, and operating system choice. Knowing this information greatly helps you make informed decisions later on. For the sake of argument and a point of reference, consider the following hardware setup:
- Two Linux systems
- Two Windows NT systems
- A PowerMac running Mac OS 8.6
- A 10-BaseT hub connecting them all
- @Home cable modem service
- Extremely sensitive data contained on each system