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BUSINESS TECHNOLOGY CONSULTING FOR NORTHERN UTAH

Considered one of the most critical aspects of today's computer networks, the firewall has evolved tremendously over time. In today's broadband world the importance of "blocking" unwanted traffic is higher than ever. Even Microsoft has begun implementing a firewall into the new versions of WindowsXP. So are you still confused how this works or why it is important? Let's try to clear up the questions.

What is a Firewall??

Definition: Hardware or software designed to prevent unauthorized access to or from a private network. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet. All traffic entering or leaving the network passes through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

Technical: All Internet traffic has two critical pieces of information: an IP address and a Port number. Having an IP Address and a Port number makes a "socket". Most people have seen the TCP/IP setting on their computer and are familiar with it. An Internet Protocol (IP) address is number like 100.150.200.250. If you want to know what your IP address is try the IPCHICKEN website. What we don't see is the Port numbers. Virtually all web pages that we view with a browser work on Port 80. Email functions on Ports 25 & 110. There are over 50,000 ports out there. Click HERE to see a list of assigned ports.

What does a Firewall do?

Overview: A firewall acts like a filter stopping or allowing internet traffic based on preset rules or customized requirements. The firewall protects computers from hackers trying to get into their equipment. Also, if a computer was infected with certain viruses or spyware the firewall can stop those items from being able to access the internet over non-standard ports. Firewalls can be used to stop certain programs from working correctly. Shutting down port 23 will stop any Telnet traffic. If you want to shut down your employees from playing "Doom" across your network just shut down port 666.

What qualifies as a firewall?

Hardware: A hardware firewall is a physical box that is placed on the wire between the access to the outside internet and the inside network.

Here are some companies that make hardware firewall appliances:

Software: While a hardware firewall is a great appliance to have on your network it is normally too expensive for a home computer user to justify. Enter the software firewall. These vary widely in function, features, and effectiveness. Don't forget if you have WindowsXP with service pack 2 installed you already have a pretty good firewall just waiting for you to activate it. Other choices can come bundled with anti-virus software and might be a more logical solution. Here are some links to some options: