Do you need a firewall?

Yes!!!

Think of your computer as a building and the doors are all the different ways to the Internet. The computer calls these doors "ports". Your computer has thousands of these doors, and a firewall will keep them locked.

The bad guys have programs that will go out on the Internet, find your computer, and start knocking on all your doors. Without a firewall, your computer will say, "Hey, welcome! C'mon in." The bad guy can now control your computer without you knowing it. They can search your computer for files that contain personal information.

Modern firewalls not only lock your doors, but will not even respond to the initial knock at the door. This is good because without an answer, the bad guy program assumes that it has reached a bad IP address and moves on to find another victim. 

Some doors have to be open. Want to surf the Internet? You have to have port 80 open. Want to send and receive email? Then you have to have ports 110 and 25 open. That's okay. Some doors are fine to leave open, but you don't want a whole bunch of doors open if they don't need to be.

A good firewall program will detect when someone or something is trying to open a door and it will stop and ask you if it's okay. You should have the option of denying the connection just this once, denying it permanently, granting the connection just this once or granting it permanently. Here is a general rule of thumb: 

• If you open a program that you will be using on a daily basis, and it asks you to grant or deny the connection, go ahead and grant it permanently. 
• If you just installed a program and it needs to go on the Internet for registration purposes, then grant it just this once.
  
• If the program needs to go to the Internet for updates, this is up to you. How often will you use the program? How often do updates come out for this program? If the program is updated monthly or longer, I'd grant it just once each time.
• If the firewall asks you to grant a connection and you did not just install a program, or try to access a web page that wants to install an ActiveX control or something similar, then definitely deny the connection. If you're unsure, deny it just this once. Investigate the issue so you can make a better decision next time. 
• If the firewall wants approval to grant access to something you were not involved with at all, deny it permanently.

There are many firewalls on the market to choose from. They all do the same thing just with a different look and ease of use. Some firewalls are "hardware" which means that it is an actual box that you connect directly to your ISPs modem. Then your computer or your network is plugged in to this unit. This is the best form of firewall but is not as user friendly as a "software" firewall which is installed on each computer. For the best protection, use both a "hardware" firewall and a "software" firewall from different manufactures. This is called multi-layer protection. It will be a lot harder and almost impossible for the bad guy to get through to your system. 

Protecting your data should be your number one concern. Even if you think to yourself that you don't have anything on your system that anyone would want, think about everything you have ever typed on your keyboard. If the bad guy has access to your system, chances are he's got more than you know.

That might be a good topic for another blog... 

If you need help with firewall advice or you are having trouble with your network, then you really need to talk to a professional. You should call Networthy Systems. If we can't help you, we'll point you in the right direction.

Thanks for reading.

Thomas Johnsen - CCNA, MCSE+Security, MCDST, A+, Net+, Security+

Lead Engineer

Networthy Systems

6950 College Street Ste. G

Beaumont, Texas 77707

(409) 861-4450

http://www.networthysystems.com