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Tuesday, November 18, 2008

Firewalls and ZoneAlarm Guide and Tips

Firewalls - what for?
Firewall is a either a hardware based solution or a program, that is meant to limit access to your computer from the network, and on the otherhand from your computer to the network. There are plenty of different firewalls, but the ZoneAlarm firewall described here is simple, reliable and free. If used properly, firewall gives you excellent protection against direct attacks from the network, because computers ports cant be seen in the network if the firewall is setup properly. If there where open ports on the computer, that would basicly mean that there was some service open which is possible to be contacted via net. As there are no ports available, naturally there is nothing to contact with from the net. With proper firewall, one can also very effectively prevent the computer to be transformed into "zombie" or otherwise became under some hackers command, even if the settings on the computer where insecure or harmfull programs are run in the computer.
However, it must be stated clearly that firewall does NOT replace antivirus software or being cautious. It doesnt prevent files on your computer to be corrupted nor spreading of viruses and worms. It does, however, usually prevent harmfull trojan horse programs and other backdoor programs from contacting net and opening your computer to some hacker. It also prevents programs from sending information about you to their manufacturer (like spyware programs)if you dont allow the particular program to go access internet.
At this point, I need to mention about WindowsXP:s "firewall". In short: Avoid it if you can! It only closes inbound ports from connections. It doesnt prevent outbound connections or specify which programs can connect to net. So, dont use it. Get rid of it totally and install ZoneAlarm or similiar instead. Also, you may have heard about "Black Ice Defender" or "BID". Again, forget it too. Its NOT a real firewall, its just an inbound port blocker. It doesnt allow outbound filtering. Some people find it usefull to check who is knocking their ports, but otherwise its pretty much useless. Get rid of it and install REAL firewall like ZoneAlarm.
If you are using WindowsXP SP2, then your might not need to bother yourself with installing ZoneAlarm. SP2 Internet Connection Firewall does its job much better than earlier versions of it. If you dont want to mess with 3rd party firewall like ZoneAlarm, stay with SP2 Internet Connection Firewall! Also, ZoneAlarm does not work with latest versions of F-Secure products, so if you are using F-Secure, better dump ZoneAlarm and trust ICF or F-Secures firewall (if it has one!)...
However, please notice, that before you have option to go to internet and download ZoneAlarm, you NEED to have some firewall running to block inbound traffic...if you dont, your computer gets infected before you have installed ZoneAlarm. In this case, use WindowsXP firewall, you can find the guide on how to enable it in my Win2k/XP page

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