I need to have the mac take traffic coming into it on one port send the traffic to a different but still local port.
I.e. Traffic comes in on port 1234 and transfers to port 5900 (vnc)
This is because the router wont allow me to set up portforward where the origin and destination ports differ and I need to connect to multiple machines.
So for example in my router I have set up: port 1234 -> 192.168.0.2:1234 port 1235 -> 192.168.0.3:1235 port 1236 -> 192.168.0.4:1236
Then I need the mac to take incoming port and send it to local port 5900