Note: As you read this information you should keep a couple of facts in mind. First: Sunbelt Software has recently purchased Kerio and they supplied this information. Therefore it may be slightly biased. Second: The information we have on this products accessibility is based on experience with earlier versions. We can't be sure the new versions will be as accessible.
Every week, I get questions from readers about how to best protect their computers from Internet threats. Viruses, worms and Trojans get a lot of media attention, and some people think that as long as they have a reputable anti-virus program installed, they don't have anything to worry about.
Unfortunately, AV protection is only part of the solution. You also need a firewall to prevent attackers from getting into your computer (and home network, if applicable) by exploiting vulnerabilities in the TCP/IP networking protocols, operating systems and applications running on your computer. If you use your home computer to connect to your company network, it's even more important, since attackers could use your system as a conduit to get to the business LAN.
XP comes with the Internet Connection Firewall (ICF) out of the box, and Service Pack 2 upgrades it to the Windows Firewall. These features give you basic firewall protection against incoming attacks, but if you want more flexibility and configurability and the ability to control programs' access to the Internet, you'll need to install a third party product.
There are plenty of reasonably priced "personal" or host-based firewalls to choose from (so called because they install on and protect a single computer, as distinguished from expensive network-based or perimeter firewalls installed by businesses to protect entire networks). Sunbelt Software recently acquired one of the best, Kerio Personal Firewall, and since we've been getting some questions about it, this week we decided to test and compare Kerio and some of the other popular personal firewall products on the market.
Along with Kerio, we took a look at ZoneAlarm 6 from Zone Labs, Sygate Personal Firewall 5 from Symantec, and Outpost free firewall from Agnitum. Here's what we discovered:
All four of these give you basic protection from port scans and other well known attacks, and some control over programs, but some were easier to use and/or more configurable than others. Here are some of the things we like about Kerio, in contrast to the others: it gives you a choice of modes that includes full program control.
Kerio running in this mode gave us a higher level of protection than any of the other choices. Kerio Pro includes a lot more just firewall functionality, too - you get intrusion prevention, Web filtering and remote administration. these are features usually found in high dollar commercial-grade firewalls.
For best protection, you may need to do some customized configuring. In default mode, Kerio blocks inbound traffic and allows all outbound traffic. But by enabling the Application Behavior Blocking feature, you get protection against malicious programs trying to access the Internet or local network.The Kerio firewall is recognized by Windows XP SP2. This means the XP Security Center won't pop up, telling you that you're unprotected, as it does with firewall software it doesn't recognize.
How do the others compare? Sygate was pretty easy to configure but it didn't block outbound access quite as well as Kerio in full program control mode. It also didn't let you allow or block specific programs, although you can allow or block specific ports. ZoneAlarm's free version didn't do as well as Kerio or Sygate at blocking outbound access. Outpost similarly didn't do a good job of blocking outbound access, and unlike the others, also didn't do so well with direct attacks. It does offer detailed settings and some extra features like keyword filtering, but in our experience that feature didn't work as well as we'd have liked.
In order of preference, we'd choose Kerio first, with ZoneAlarm and Sygate coming in close together in second place. Both of them did a good job of blocking inbound access, and blocked some unauthorized outbound access. If you want the most flexibility and the best control over outbound traffic, we recommend Kerio.
Return To Software Firewalls Page Return To Resource PageUpdated on ... December 09, 2006