Port Forwarding (80 to 8080 for Tomcat) Using IPFW on Mac OSX Here I show how easy it is to set up port forwarding (80 to 8080 for Tomcat) on Mac OSX using ipfw from the Terminal. IPFW is the built-in firewall of Mac OSX and we can quickly set up a firewall rule to allow port forwarding... Step 1: View current firewall rules.