How safe is your computer on today's Internet?

When you get a computer, from the computer store, private seller, or anywhere, the chances are it will not come with a Firewall. What is a Firewall I hear you say!? well, this is what it is:

A firewall is a piece of software that stops other computers connecting to your system.

Well, that might sound strange, I hear you say! "why would I want to stop people connecting to my computer? how I will I download stuff!?". Here's a way to look at it:

Your computer has ports, and there are two types of ports: Physical Ports, and Virtual Ports.

Physical ports are ports like your keyboard port, or mouse port. They are physical connections on the back of your system that things connect to. Virtual ports are the same, only that they are software ports, ports which other software on other machines connect to. A typical machine will have thousands of ports, all doing something that the user is probably never aware of, and will never concern them anyway. Just to make things a little easier:

When you look at a web page, the server that stores the page you are getting connects to your machine via port 80. This is considered safe and routine, since port 80 only transfers HTML which is basically text (nothing to destructive). When you send an email, your machine connects to the servers port 25 and so on. 

So, back to the firewall:

The firewall knows which ports are ok to use and which ones can cause problems, for example, some Trojans are designed to get into your machine and open a port without your knowledge, usually port 1999, then a user can connect to your machine and do what ever they like to your files. 

However, the firewall can run in the background while your on the net and 'listen' on all these ports (up to a thousand) and if someone tries to look into your files, it will kick them off of your system and report to you there details. 

Firewalls are not cheap, and the free ones you can download will only monitor a small percentage of the dangerous ports.

There are two leading firewalls on the market today:

TDS:

TDS: Trojan Defence Suite. One of the best and most advanced Anti-Trojan systems on the net today. This program has a small license cost attached to it, but it's well worth it! It has the ability to scan your whole system for known Trojans, allow the users to control access to certain ports, and monitor Trojan activity on other systems! Click here for more details.

Norton Internet Security 2001

NIS has some really cool features as well, although not as powerful as TDS, it has the ability to interact with Norton Antivirus giving you much greater protection over Trojans and viruses. It will also allow you to shut of ports, stop websites scanning you and a really cool feature that allows you to de-activate un-authorized advertising on sites, speeding up the web overall and stopping those annoying pop up windows. Click here for more info.