Limewire for OSX & NAT based modems

[Stef]

In the murky waters of being a NEWBIE, here's the following, I got limewire for Mac OSX (latest version?) and in a way i am happy, reasonably quick, using a G3 B&W/350 and a NAT-based ethernet modem, DSL 400ish, no up-loads....(prob cos' of NAT) I want to use the mac built-in firewall (and I cannot specify -at least i don't know how!- the port for limewire) and it seems I am not able to 'push' my IP in the optionsbox (sort of stripped compared to the 9.x linewire)... So, well, after reading Lee Ware's article in optimizing up- & downloads it seems i know 'nothing'.... What is the IP adress I should push... I got an external IP (www.whatsmyip.com), I got an IP for the modem AND an IP in my Mac...EEHHH?? Lee states here is much to know about NAT based stuff, is there a site where they have an NAT-FAQ? And are there deliberate changes in the MacX Limewire?

I would really like to have some more information on the subject, please!

Kind greetz, Stef