Although I'm not suggesting you'd want an icon of a wildly gesticulating robot running around on your computer screen every time your computer shows some sort of network activity, you definitely want to know what kind of network traffic is being generated by or targeted at your network-connected computer. If you're a serious networking techie, you can sit down with a packet analyzer and trace the packets that move across your network. But even if you know what's going on over your networks, you don't necessarily have any control over the activity. And if you're an average (or even above-average) computer user, you probably don't care much about the network traffic unless it could harm your system. Hence, a product like Zone Labs Zone Alarm 2.6 is a good place to start.
Zone Alarm 2.6 is freely available for personal use, so you can't beat the price. The download is small (2.6MB) for those of you still on a 56Kbps connection. And Zone Alarm supports all of the current Win32 platforms, so you can install the firewall on your Windows 2000 or Windows 9x computers equally easily.
When you launch Zone Alarm the first time, the program brings up a quick, seven-panel walkthrough about what the product is and what it does. The explanations are simple and reassuring to even a nontechnical user. Accepting the default settings gives your Web browser access to the Internet, but any other application that tries to access the Internet from your computer will trigger an alert and open a permissions box (see screen shot).
For my small office/home office (SOHO) network, I needed to explicitly allow communications on the address range 192.168.0.0 – 192.168.0.255 (as generated by my DHCP server) so that communications among my computers, printers, and network shares didn't generate alerts requiring user interaction.
After I installed Zone Alarm, I just let the program do its thing. Every time I launched an application that talked to the outside world, an alert popped up and asked for permission to give the application the access it needed. My first sets of applications were those I use all the time and that need network access (email and the like). I clicked the checkbox that lets Zone Alarm remember my preference so that it wouldn't prompt me in the future.
One application I use is advertising supported, so the application sends messages and requests to an Internet server for the advertising information. For those requests, I've said No, but didn't tell Zone Alarm to remember that choice; I wanted to see the application's behavior if it couldn't acquire the advertising information.
Generated alerts also contain a More Info button that takes you to the Zone Labs Web site for information about the alert type, whois info on the IP address that wants to be contacted, and more.
If you have one system connected to the Internet in your SOHO or home environment, Zone Alarm 2.6 is definitely worth a look. But if you want to run the product on a system that provides Network Address Translation (NAT) via Internet Connection Server (ICS) in Win2K, Windows Me, or Win98, you'll probably want to upgrade to the paid version of the software, Zone Alarm Pro, for $39.95.
Zone Alarm Pro 2.6 adds several features, but the most important to the SOHO or home user is automatic network detection. This feature can find and identify both of the networks that your NAT/ICS machine is running on and configure the minimal network access necessary for the machine to provide secure Internet access to all the client machines in the network, although Zone Labs recommends that you install Zone Alarm on every machine that talks to the Internet.
In short, both versions of Zone Alarm are simple to install and easy to use. The only problem I've encountered is that Zone Alarm Pro doesn't like to coexist with the software for DirecPC satellite broadband. When I installed Zone Alarm Pro on the same system as the USB satellite modem, I got an error message stating that the satellite device's signal strength was too low, even though I could still connect to the Internet from other machines on my network. Then I got a message saying that the satellite adapter couldn't be found. Authorizing all the DirecPC network requests didn't help, although the traffic continued to flow. Uninstalling the Zone Alarm Pro software made the errors go away, so for now, I'm running Zone Alarm only on the client systems, not on the system that runs the satellite connection. I'll update you when I find a solution to this problem.