Sorry I wish I had more information on this (I will try to get more later) We have a dell 17r laptop at home that we use to connect to our netgear router via ethernet. All other devices in our house connect via wifi approx 7 wifi devices connected.
I have access to the internet with all wifi connected devices but when I turn on the 17r that is connected via ethernet it does not connect to the internet and other devices lose their connection as well. It as if it has to be ethernet or wifi on not both.
I have read tha some apple routers are this way could this be the case with my router. It is pretty new. I will try to post a model number later.