Understanding Firewall protection

In buildings, a firewall is a barrier that prevents a fire from spreading. In computers, the concept is similar. There are a variety of "fires" out there on the Internet-hacker activity, viruses, worms, and so forth. A firewall is a system that stops these attempts to damage your computer.

The Zone Labs security software firewall guards the "doors" to your computer-that is, the ports through which Internet traffic comes in and goes out. Zone Labs security software examines all the network traffic arriving at your computer, and asks these questions:

What Zone did the traffic come from and what port is it addressed to?


Do the rules for that Zone allow traffic through that port?


Does the traffic violate any global rules?


Is the traffic authorized by a program on your computer (Program Control settings)?

The answers to these questions determine whether the traffic is allowed or blocked.

Choosing security levels


Setting advanced security options


Managing traffic sources


Blocking and unblocking ports


Understanding expert firewall rules