Did you set up a Static ip before you did the port forwarding? That must be the very first thing you do, else you need to cancel your port forward rules & repeat.
From memory with D-Link, you need to reboot the router to both save the settings properly and to get them operational also, I might be wrong. Did you do that? Rebooting the computer may also help. Just a few suggestions to try.
I had a D-Link some years ago.

Do you use a software firewall also? If yes, add the program to both it's UDP & TCP exceptions. Be sure it's both. OH .. and also for the router. Many gnutella clients use both tcp & udp for their communications. I think in the case of D-Link, you choose ALL (ie: both tcp & udp.) It's been a while since I used my d-link (it was only adsl1.)

Rebooting both the router and the computer should do the trick if you did port forwarding correctly. Rebooting the computer refreshes the memory & the external ip address, etc.

For setting up a static ip address for Debian, not sure these will help:

http://www.techiecorner.com/486/how-...-ip-in-debian/

http://www.debian-administration.org/articles/254

http://wiki.debian.org/NetworkConfiguration

http://www.nflug.org/pipermail/nflug...ly/021014.html

http://www.cyberciti.b iz/faq/linux-configure-a-static-ip-address-tutorial/ (remove the blank space)