This 'might' help someone. I had the above router. The cable modem was reporting good internet and confirmed with a computer via Ethernet. Whenever I tried to set up the router, the internet did not work and connecting via wireless was impossible.
I did a hard reset - went through the usual setup and everything looked ok (internet and wireless) then in the middle of connecting my apple tv's, lost internet and then lost the wireless.
I had to do 2 more hard resets before it finally worked. I was able to do the setup via the app. The only difference on the last setup via the app was the app reported the firmware was updated.
I think it was in the middle of the firmware update and this is why I lost internet. Apparently there is no - Yes update the firmware option so it does it automatically. Unfortunately you lose internet while the firmware is either downloading or when the router is updating the firmware and you just need to be patient.
