I did a succesfull experiment in this matter.

I directed both all TCP and all UDP ports to the PC on the LAN. (so all 65536 portnumbers) And I could connect and play with a server over the internet.

I have put the following 2 lines in my NAT32 startup file



ppmap add tcp 0:65535 192.168.0.2 0

ppmap add udp 0:65535 192.168.0.2 0



where 192.168.0.2 is the adres of the PC on the Local network (LAN).

So all incoming TCP and UDP packets are directed to this PC.

I will try to narrow this down a little and report on that later.