WR1043ND is connected to LAN port of your home router with DHCP disabled? If so, you don't have to configure WAN on WR1043ND.

The current firmware version is too old... Download and upgrade the latest firmware. Reset and reconfigure it. http://www.tp-link.com/en/download/TD-W8968_V3.html#Firmware If the problem continues,...

One-to-One NAT take effect only when the connection type of WAN is Static IP. http://www.tp-link.com/en/faq-381.html

WAN Setup: WAN Connection Type "DHCPV6" Select "Get IPv6 prefix delegation" LAN Setup IPv6 Address Assign Type---Try "DHCPV6" or "SLAAC"

You may have to change securility settings on web interface of your W8960N. Since it is secured with WPA2-PSK currently, try WEP or disable security to see if your Nintendo DS game can connect...

Connect your PC to the modem directly and ensure you can access internet in that way. If not, contact your ISP. On your router page, since there is no WAN IP address. You may reset the router to...