How many ports does limewire need/want for function?

I open the options/Advanced/firewalls and click force ip and enter the ip of my linksys router and the port I forward for limewire.

There is another place that asks for a port:
options/Advanced/port and I enter the same port as in the above.

Why are there two places for port?

Should I forward a second port so that hosts and uploads are different and would that work?

It does not seem to be necessessary but would it be better?

-bye for now