Door Stop X Editor's Review

'Door Stop X' is a Mac OS X firewall.

I see that the producer of this program refers to it as a 'firewall'. I have seen almost everything that this product has to offer, except the 'firewall' part. I believe that this product is a front-end for the Mac OS X built in firewall, ipfw. I had some doubts, so I checked this with WaterRoof, an Open Source program that is an ipfw front-end.

The test was quite simple. I flushed all the firewall rules by using WaterRoof, except the rule number 65535 (allow IP from any to any) which cannot be deleted, then I started Door Stop with all the defined rules set to deny. I refreshed the ipfw's list of static rules that had only one rule in it (65535) with the WaterRoof application. You could easily guess. A new set of rules populated the ipfw rules list right after starting Door Stop. So where's the 'firewall' part of this product? I couldn't see any. I wouldn't suspect anything, if I wouldn't have read the Door Stop's firewall log, which in fact is the ipfw's log. I agree that this application adds some functionality to the built-in firewall, but it's not a firewall.

Besides the fact that the application uses the built-in firewall, this application is quite a good application. You can easily define rules in your firewall, depending on certain Macintosh services or applications. Defining new rules is easy, because the interface is intuitive. When using this program, the firewall configuration is much easier than when working with the Terminal from a CLI (command line interface).

The 'Preferences' panel doesn't give you many options. You can find in the 'Advanced' section some options that can influence the program's behavior. You can check if the firewall should protect the UDP as well as the TCP protocol, you can use a stealth mode, or you can disable IPv6. You can also customize some interface options, such as 'Show Tool Tips' and 'Show Door Stop X status in menu bar'.

Pluses: It allows you to configure your firewall easily, it has good documentation. However, some knowledge about network and firewalls is required to obtain an optimal configuration.

Drawbacks / flaws: This product works for Mac OS X 10.3 and 10.4 operating systems that have a built-in ipfw firewall. Since my test proves that it uses ipfw rules table, I believe that this program is just a front-end for something that comes with your Mac OS. So far, I'm not convinced that this program is a firewall by itself.

In conclusion: The application makes your life easier by saving time. If you are still interested, then you can also check some alternatives: Flying Buttress and WaterRoof.

version reviewed: 2.0