hey change your mac address on your xbox. on the xbox go to "settings/network/config network/advanced settings/alternate mac address. type in 00125A??????
the question marks are 6 numbers that you choose. and leave everything else as automatic. restart the xbox and on fsd there should be a new ip address, WRITE IT DOWN then do the link test with upnp enabled, if it fails dont worry try to do link any way try black ops 2 on title update 9 and select your room before joining a game. if that works GREAT! then go to xbox official dash and and go to network settings, write it all down, then put it all in again this time as manual static ip, using the ip address that fsd gave u after the restart. then after that go on routr and put the xbox into the DMZ and now you should get pass pass on the test and link may work for you. if it dont work keep bumping up the ip address or try again.
GOOD LUCK