If you’ve ever needed to limit bandwidth on a certain port in OSX you’ll be happy to know that OSX comes with the ipfw firewall of FreeBSD fame.

Here’s how to use it to limit bandwidth on a port:

Create a pipe:

sudo ipfw pipe 1 config bw 50Kbit

Attach the pipe to port 80:

sudo ipfw add 1 pipe 1 src-port 80

To delete it:

sudo ipfw delete 1