CM1150V will not work with either of my WiFi Routers or Voice service

I purchase the Netgear Nighthawk CM1150V tonight and spent over 5 hours on the phone with Comcast and Netgear but ended up having to switch back to my rental modem. For some reason the modem does not dish out an IP to the router and the router cannot connect to the modem. If I plug a computer directly into it the wired comouter gets internet. but when I plug a router into port one it doesn't work. For some reason the Voice also doesn't work.