To use with Comcast / Xfinity: 1) plug in modem, attach coax, and connect port 1 to a laptop with Ethernet cord 2) go to xfinity setup webpage on your laptop and enter account credentials to activate modem (web page address is in instruction manual) 3) modem will reset and then you should have wired web connectivity with your laptop
https://www.amazon.com/Motorola-MB7621-Approved-Spectrum-Downloads/product-reviews/B077BL65HS