Norton Personal Firewall 3.0.3 (NPF) is a friendly app that’s easy to configure and protects your computer from unauthorized access by keeping an eye on incoming network traffic. NPF supersedes Apple’s built-in firewall, offering you protection that’s ample, easy to access, and simpler to configure.
Once you’ve installed and opened NPF, you can choose to go through a brief, guided setup process, which allows you to select from three levels of protection and notification, each of which provides progressively more protection.
The most basic setting, Minimal, only monitors active FTP connections. The Medium setting puts the firewall into Stealth Mode—a way of hiding your Mac from others on the Internet or your local network—and monitors your Mac for suspicious outgoing activity, a possible sign that malicious software is using your Mac for unauthorized purposes. The Maximum protection setting looks for suspicious incoming activity while monitoring both incoming and outgoing UDP. (User Datagram Protocol) traffic (UDP is an Internet protocol used by some streaming media and VoIP applications.) The program is intelligent enough to recognize applications you’re using that require UDP access and will allow those applications to freely access the network.
If those three settings aren’t enough, you can configure NPF to filter network traffic based on specific ports or message types. For example, when I first installed NPF, I was unable to share my iTunes music library. To fix the problem, I added iTunes music sharing on port 3689 to Norton’s protection list, allowing both incoming and outgoing access, and my library was instantly available.
Unfortunately, Symantec Norton Personal Firewall’s Stealth mode isn’t quite as stealthy as it should be: Someone trying to hack your Mac could still find out that there was a potential computer out there to play with. But, even if your Mac is not totally invisible, the program offers sufficient protection against unauthorized access.
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Symantec’s Norton Personal Firewall 3.0.3 is a simple and effective firewall application that’s easy enough for novices to use, yet powerful enough to protect your system and offer a wealth of configuration options.
[ Jeffery Battersby is a network analyst and a regular contributor to Macworld.]Norton Personal Firewall’s control panel offers easy access to most configuration options, which should offer adequate protection for the majority of users.