How to get open NAT on 2 consoles using the same connection?

Im using a Netgear CG2100D, and one xbox is connected throught the ethernet cable and the other on the wireless network. The following ports are forwarded to the wireless xbox local ip address 3074 tcp and udp, 88 udp. Upnp is enable however only seems to show the 3074 ports on the other(non wireless xbox). Any help would be great