New Airport Extreme (802.11n): : Port Mapping... ***???

Question

There are two different programs I was formerly using, whereby (after following instructions) I was able to create a static IP address for every machine on my network, plus open ports 8000 and 9990-9998 respectively. But ever since upgrading to the new Airport Extreme (802.11n), it completely stopped working. To boot, I've upgraded to Leopard on one of two of the machines (the other is still using 10.3.9).
I haven't been able to figure out for the life of me, how to configure it. It's no longer as obvious where and what information to put in. All guides that would remotely help are designed for the older Airport unit, which has completely different menus in the Airport Utility.
Is there anyone out there who has experience with Dot-Tunes and/or Nicecast or similar port mapping, who has the patience to describe, in layman's terms, what steps to take to get this set up correctly again, starting with how to reassign static IPs for my machines. I will not ask a lot of questions and take up too much more of your time. I'm just frustrated after a whole day of trying to figure this out and fruitless Google and forum searches.
Thank you so much.

Answer 1

I'm not familiar with either Dot-Tunes or Nicecast, but the following would be the general port mapping procedure with the 802.11n AirPort Extreme Base Station (AEBSn) using the AirPort Utility. Note in this procedure you will not need to assign a static IP address for each of your host devices. Instead you will be taking advantage of the AEBSn's DHCP reservations feature.
To setup port mapping on an AEBSn, either connect to the AEBSn's wireless network or temporarily connect directly, using an Ethernet cable, to one of the LAN port of the AEBSn, and then use the AirPort Utility, in Manual Setup, to make these settings:
1. Reserve a DHCP-provided IP address for the host device.
Internet > DHCP tab
o On the DHCP tab, click the "+" (Add) button to enter DHCP Reservations.
o Description: <enter the desired description of the host device>
o Reserve address by: MAC Address
o Click Continue.
o MAC Address: <enter the MAC (what Apple calls Ethernet ID if you are using wired or AirPort ID if wireless) hardware address of the host computer>
o IPv4 Address: <enter the desired IP address>
o Click Done.
2. Setup Port Mapping on the AEBSn.
Advanced > Port Mapping tab
o Click the "+" (Add) button
o Service: <choose the appropriate service from the Service pop-up menu>
o Public UDP Port(s): <enter the appropriate UDP port values>
o Public TCP Port(s): <enter the appropriate TCP port values>
o Private IP Address: <enter the IP address of the host server>
o Private UDP Port(s): <enter the same as Public UDP Ports or your choice>
o Private TCP Port(s): <enter the same as Public TCP Ports or your choice>
o Click "Continue"
(ref: "Well Known" TCP and UDP ports used by Apple software products)