Why is my Xbox Nat Always Strict?

Disconnect your router from your wall socket for 1minute. disconnect your wireless adaptor or ethernet cable. Plug everything back like normal, then dont sign in to xbox live but go to network settings, then search for your network, type in your WPA password and reconnect to xbox live this should refresh your network and hopefuly fix the problem, it worked for me but i had to do it twice for some reason.