Intruders from the Internet

Another danger to protect your computer against is someone accessing your files from the Internet. This is most apt to happen if you have file sharing turned on on your computer and have no firewall to protect you from intruders on the Internet.

The potential danger from intruders is much greater if you have a broadband - DSL or cable modem - connection to the Internet. That's because with a broadband connection you are connected to the Internet all the time, giving intruders a greater opportunity to enter your system.

There are two approaches to keeping intruders out. The first is a software firewall that examines traffic between your computer and the Internet, looking for activity that you didn't initiate.

Software Firewalls

If you are using Windows, there is a firewall which is part of the operating system. Follow the link in the Links box above to get information on using it.

Other commonly used software firewalls include those from the computer security firms such as Norton Personal Firewall and McAfee Personal Firewall Plus (see the links). There are several that have free versions, including Zone Alarm.

Zone Alarm, a product of Zone Labs, also monitors outgoing traffic, which means it's able to detect activity by Trojan Horse programs.

Hardware Firewalls

A more common approach is it use a hardware firewall, which often provides WiFi access as well. They can be faster than a software firewall because they reduce the amount of work your computer must perform. They also have the additional value of easing the connection of more than one computer to a single broadband connection.

The terms Router and Firewall are used in different ways by different manufacturers. What distinguishes the individual products is the functions they provide. Most commonly both functions are contained in a single device.

Generally routers are lower-cost devices often suitable for home networks. Linksys, D-Link and SMC may be the major manufacturers in the group.

Before and after you install either a hardware or software firewall visit Shields Up (a link is above) and run the security test offered there. The program will tell you how vulnerable you are to intruders.