[clod]

How can I open up a network port on my iMac through the command line or SSH?

[suthercd]

Through the Firewall tab in the Sharing prefs.

Craig

[entrox]

Read the manual for `ipfw'.

After reading the manual, you can try `ipfw add 03000 allow tcp from any to any <port> in'

[Camelot]

Of course, editing ipfw only means that the firewall doesn't immediately drop the packet when it hits your machine.

Unless you've got some service running on your machine listing to that port, changing IPFW isn't going to make one iota of difference.