hey i dont know much about setting up routers and stuff but i had a problem with the wii connecting and no my ds
here's what i did:
i got my ISP address for my computer, had to add "10"
ex 111.111.111 to 111.111.121
set my dns on the DS to 255.255.255
and it worked.
check Nintendowifi.com and follow the troubleshooting tips for DS, thats where i got my info.
hope this helps!!!