Xbox wont connect from router to internet?

i have a new Xbox slim and when i try to get on Xbox live it says disconnected and then i test it and it connects to network and then it doesn't to the next step and i have plugged an Ethernet cable to it and then used my wireless net gear adapters and then it was doing the same thing....but then i hooked it up to my blu ray and it worked and i am on the computer right now and the Internets working how can i fix this