Four Personal Firewalls Reviewed

Version 3 of Norton Personal Firewall 2001 alerts you to intrusions, maintains an event log of connection incidents, allows only applications you specify to use the Internet, permits cookies only from Web sites you've authorized and blocks both Java applets and ActiveX controls by site. Its AutoBlock feature detects and thwarts port scans.

Via a series of dialog boxes, you tell this highly configurable firewall which applications you use to access the Internet, which Web sites' cookies, applets or ActiveX controls you'll accept, and what actions the firewall should take when it detects an intrusion. You can also tell Norton Personal Firewall 2001 to optionally block all message traffic from an intruder for a set amount of time. The Norton Internet Security 2001 suite download is a hefty 10.9MB.

Aptly named for its small download size of 1.3MB, Tiny Personal Firewall is in all other respects not so tiny. It's a feature-rich product with a rule-based TCP/IP filter that detects intruders, foils Trojan horses by preventing unauthorized applications from accessing the Internet, ensures Trojan horses can't pose as trusted applications by verifying that a program has an MD5 digital signature and logs security events. Tiny Personal Firewall can even send its log entries to a central server for reporting purposes.

Tiny Personal Firewall discriminates between sites you trust and all others on the basis of IP addresses, address groups or subnet ranges. It offers remote administration, and you can specify when during the day a filtering rule should be applied.

Besides detecting and spoiling intruders, BlackIce Defender tracks them down and does everything except handcuff them. It performs a comprehensive backtrace to find an attack's origin and identify the hacker. Depending on what information is available, BlackIce Defender reports the intruder's IP address, NetBIOS name, Domain Name System name, permanent network adapter (MAC) address and other data. The firewall software stores the evidence of each attack in its log file. It's like having Caller ID turned on for Internet hackers.

Although BlackIce Defender's default (preset) firewall configuration is thoughtfully crafted and suitable for just about any mobile computing situation, the product has an intuitive user interface, and you don't have to be a firewall expert to operate BlackIce Defender. Its alerts are color-coded and easy to understand. BlackIce Defender is a 3MB download.