Chapter 3 The Zonealarm Personal Firewall - Watchguard Firebox SOHO 6 Client Manual

The ZoneAlarm Personal
CHAPTER 3
Firewall
A personal firewall is a barrier between your computer and the outside
world. The computer is most vulnerable at its doors, called ports. Without
ports, no connection to the Internet is possible.
ZoneAlarm protects these ports by following a simple rule: Block all
incoming and outgoing traffic unless you explicitly allow it for trusted
programs.
When using ZoneAlarm, you often see Program Alert dialog boxes
similar to the image below.
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