Here are the basic steps for configuring port mapping (forwarding) with the 802.11 AirPort Extreme Base Station (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"
