Ok, that gives more info.
One thing that I noticed about the 2680 is that the router behaves differently when in a AP node configuration when using the LAN port. I noticed that last time I tried, the router would not work right in AP mode using the LAN port. Other or older D-Link routers, one can configure the router by setting a different IP address for the router, i.e. 192.168.0.1 gets changed to something that is with in your host routers DHCP IP address pool. Then disabling the DHCP server on the D-Link router, then after the changes are set, one would connect the LAN port of the D-Link router now in AP Mode and connect it to the LAN port of the host router. The D-Link router should connect and start to pass internet traffic thru the router in AP mode to any thing connected to the wireless on the router or to the other LAN ports. With the 2680, D-Link changed something that caused this not to happen or work right.
I need to get mine out again and see if anything has changed since last time I tried this.
I guess you'll need to use the WAN port on the 2680 if you have a host router in front of the 2680. IF so, just use the DMZ on the host router for the IP address that the 2680 gets from the host router. The DMZ on the host router will help avoid any connection issues since having two routers on the same line will cause a double NAT condition. The DMZ will help this.