How can I open a port (not application) in the OS X 10.6 firewall?
Worked for me.

I wanted to open traffic on port 70, so I entered the following:

sudo ipfw add 7000 allow tcp from any to any dst-port 70


The response from the command-prompt was:

07000 allow tcp from any to any dst-port 70


Yes, the 0 was automatically added to the rule #, so it is worth noting that any rule ID &lt; 10,000 will be prefixed by one or more zeroes.