A Handy Reference of Mac OS X's port numbers.
This tech note is a long time coming -- a handy list of what TCP and UDP ports Mac OS X uses. I've been longing for this whenever I have to deal with firewall configuration problems.
Of course, it doesn't cover ports used by ports — port numberws used by third-party programs not included with Mac OS X. You can always look at your local file system's /etc/services file; some lists like this one can be found on the web as well.
But for Mac OS X applications, you may just have to look up documentation for a specific product. SubEthaEdit, for example, uses port 30729 for its document sharing, as it states here.
Does anybody know of a technique for detecting that a particular port is blocked by a firewall, so that an application could defensively check and warn its user, rather than just failing to connect?
[Karelia Software]