Did you try plugging it in your Xbox 1st?
1st, plug in the ethernet cable to your Xbox. Unplug the Modem's POWER CABLE from the wall, fire up the Xbox, and then plug the modem back in.
Or try:
1st, plug in the ethernet cable to your Xbox. Unplug the Modem's POWER CABLE from the wall, plug the modem back in the wall, and then fire up the Xbox.
Sometimes your modem has to adjust for the Xbox.
†B†V† :hat