port forwarding

Hi,
I have been using tomato for a while and really liked it, however my router broke (got hit during an electrical storm), so i got a new one. unfortunately it doesn't support tomato.

My question is how does port forwarding work. I might be SOL on the new router, but if i can figure out how it was done on tomato, i might be able to get a hack on the new router.

I had it setup to use a source DNS name, and it was working fine. My site is hosted on DDNS, and the external party is also...

port forwarding