17.4. Using Other Third-Party Firewall Software
The combination of Mac OS X's application firewall and IPFW (configured in any of the ways described previously) should be more than adequate to serve the firewall needs of virtually any Mac user. Nevertheless, several other third-party firewalls are available that aren't based on IPFW, and they're worth looking into for two reasons. First, some of them offer novel features that you can't get with IPFW no matter how clever your rules are. And second, some of them offer clearer, more user-friendly interfaces than the IPFW front ends discussed previously. Unfortunately, the two attributes don't necessarily go together. For example, IPNetSentryX, described just ahead, is perhaps the most advanced Mac firewall in existence, but it's quite a challenge to understand. Intego NetBarrier, on the other hand, offers easily accessible firewall features but doesn't go nearly as far in its capabilities as the others listed here.
17.4.1. Intego NetBarrier
NetBarrier (www.intego.com/netbarrier/, $49.95), which I've mentioned on quite a few other occasions, includes a firewall (shown in Figure 17.11) among its long list of modules. Its range of capabilities is roughly similar to that of IPFW, and its rules function in more or less the same way — allowing or blocking packets, inbound or outbound, based on IP address, port, and protocol. You can also filter traffic by interface — for example, you can treat incoming or outgoing data transferred using ...