The key is to reconfigure the AirPort Extreme as a bridge and continue to use the D-Link router to provide both NAT & DHCP services for your entire network.
You will use the AirPort Utility to configure the Extreme as a bridge, as follows:
- AirPort Utility > Select the Extreme > Edit
- Network tab > Router Mode: Off (Bridge Mode)
Note: You may need to temporarily connect your Mac directly to one of the unused LAN ports on the Extreme during the setup phase in order for the AirPort Utility to "see" it. Once configured, and unless you made any changes, the Extreme will now broadcast an unsecured Wi-Fi network with a Network Name of something like Apple Network NNNNNN. Since the Extreme is connected back to the D-Link router, it will gain Internet access as well and provide it to any wired/wireless clients connected to it.
Thanks for your help, but it does not really address the problem. The Dlink is a non-wireless router so to connect to the AP Extreme I need to use a cable, if I plug in a cable I loose my local internet connections and WAN connections. I can talk to the Extreme using the wireless capability of the AP. But ultimately I need to connect the AP Extreme to the Dlink router and when I do it all goes down, no matter how I have setup the AP Extreme. The really strange thing is I had set the two up before and it worked, but I took it down and now I can't get it to work no matter what I try. The Dlink is a DI-808HV and I am using a MacBook Pro and an iMac to try to setup the Extreme. The Airport Utility has no problem seeing the Extreme wirelessly.