Protecting Yourself on the Internet — Part 1 Firewalls
This is part 1 of a 4-part article on protecting your computer from hackers. The entire series covers the following:
- Firewalls – this article
- Virus Protection
- Spyware Protection
- Backup Software
Firewalls
The foremost security necessary if you are connected to the Internet is a Firewall.
What is a firewall?
“A firewall is a program or a hardware device that filters the information coming through the Internet connection into your [computer]. If incoming information is flagged by the [firewall], it is not allowed through.” — [How Stuff Works]
There are two types of firewalls:
- Software Firewall
- Hardware Firewall
Software Firewall
A software firewall is a program that runs on your computer, filtering out any “unfriendly” requests from other computers on the Internet for as long as you are connected. Such programs, once installed, usually start themselves when you turn on your computer and run continuously, in the background, for as long as you computer is on.
"The perfect personal firewall would be inexpensive and easy to install and use, would offer clearly explained configuration options, would hide all ports to make your PC invisible to scans, would protect your system from all attacks, would track all potential and actual threats, would immediately alert you to serious attacks, and would ensure nothing unauthorized entered or left your PC." — Jeff
Sengstack
Important Tips -- Before installing personal firewall software on a Windows XP computer, be sure that the firewall built into Windows XP is turned off. Never use two software firewalls at the same time. Completely uninstall one before installing another. Use the vendor's uninstall utility or if not available, use the Windows XP add/remove software
tool in the control panel...” — firewallguide.com
A reader review of free or low cost firewall software is available here.
Hardware Firewall
If you have a DSL or Cable Internet connection [ with a router ] then your router probably has a hardware firewall built in. No cable or DSL modem I have been able to find has a firewall.
For extended information regarding the “box” (router) you were sold, here is a great link. NOTE: Unless you are running a web site or gaming server out of your house or business, you probably don’t need to consult this link.
While essentialy true, the section of this "Mike Holt Newsletter" about ADSL modems is not entirely correct and may give users a false sense of security.
The great majority of cheap ADSL modems & router combos on the market today are not infact "firewalls" per say. What they really are is a NATing switch that performs "Network Address Translation" on TCP and UDP packets coming from the Internet and meant for a downstream workstation and on packets coming from client stations meant for the Internet.
This allows for multiple workstations on the client network to be setup with non real world routable IP space.
The better class of device, in this catagory often does include a basic hardware firewall that will monitor and make descisions on permitting traffic flow based on source IP and port and destination IP and port.
Some ADSL modems are just that, modems, and can perform no router functions, or can perform router functions with no NAT service enabled. Each device needs to be checked and configured by the end user. This info should be communicated to the Internet community.
—Rick Kelly
Summary
- If you are connected to the Internet you need a firewall.
- There are two types of firewalls:
- If you have a DSL or Cable Internet connection [ with a router ] then your router probably has a hardware firewall built in. No cable or DSL modem I have been able to find has a firewall.
The next newsletter in this series will focus on virus protection. —Pat Curtis*
* Pat Curtis has been administering the Mike Holt web site since April 2001. If you need assistance with your web site, please contact him regarding your web site or project.
