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Desktop Firewall



Feature Comodo Kerio Sygate ZoneAlarm Pro
Version 4.3.248    
Price Free Free/Comm. Free/Comm. Commercial
ghost adapter on VPN * No   Yes
registration popup No Not in rev 248    
Zones (trusted/internet) workaround Yes   Yes
Leak test        
Component protection Yes Yes    
Notes     Not updated  

See other firewall comparisons.

2006-10-20; Installed Comodo again ( No ghost adapter problem after adjusting the VPN settings not to set the default route.

2006-07-03, Removed Comodo and ZoneAlarm firewalls because I get ghost adapter with them when using a VPN connection to the office. Kerio is on again.

2004-08-23, I tested a few desktop firewalls and antivirus programs, and some anti-Trojan programs. Sygate Personal Firewall Pro is one of the best desktop firewalls but occasionally it takes up too much processor power. This is especially noticeable when eDonkey charges the downloads at 20KB/s. Kerio Personal Firewall takes very very little processor time in the same situation. Also, Kerio has some nice diagnostic tools and options.

Kerio Personal Firewall

Pro: Shows network traffic in real time. Light on resources. Has Trusted and Internet zones.

Con: Sometimes won't start at all.

Kerio Desktop Firewall Tips

If Kerio hangs while displaying current connections, the cause is that a program that has many connections (like edonkey) is active and Kerio has "Resolve addresses" active. This will literally block the processor, trying to resolve hundreds of addresses in a very short time period.

Kerio discontinued the Personal Firewall product at the end of 2005. Sunbelt took over the product.

Comodo Personal Firewall

Pro: Free, no popups. Light on resources.

Con: Causes ghost adapter under different circumstances. Zones are set up by a wizard (creates rules that allow traffic to/from zones). Causes computer hiccups occasionally while reading from disk.

2006-12-13: Ghost adapter appears constantly.

2006-11-10: Ghost adapter appears if a VPN connection is on and the underlying adapter (WiFi) is disabled.

2006-10-23: (*) The Ghost Adapter does not appear if the default route is not set by the VPN connection.

ZoneAlarm Pro

Pro: Has Trusted and Internet (only two) zones.

Con: Heavy on resources, slow shutdown. Causes ghost adapter with VPN connection.

Zone Alarm

Zone Alarm Pro 6.5 makes Windows die with a Blue Screen Of Death after a VPN connection is established and then disconnected. After disconnecting, ipconfig shows a ghost VPN adapter with address and the original gateway. This ruins the routing table and the internet connection can not reach the DNS servers. First fix is temporary and involves removing the default gateway (default route) and creating a valid one but this leaves the ghost adapter in the system. This leads either to BSOD or inability to connect to VPN again until the computer is restarted.
The solution is to adjust settings for Internet and Trusted zones and Allow outgoing DNS requests. After this setting, disconnecting the VPN connection properly disposed of the VPN adapter, leaving no ghost adapters in the system and the routing table is in order.
This works most of the time. BSOD still appears sometimes.












In the past I tested and used several desktop firewall products. Among them were Sygate PF, Agnitum, Kerio, Tiny, Norton. Of those, Sygate and Kerio have spent the most time on my computers.

To read some firewall comparisons, check:

Firewall Net, French site version contains more info.



To test your firewall use the tools at the following links:

Firewall Net

or use some of the following software: