David has a router/modem combo. Is this common? Leo says it's common for an ISP to provide those. But keep in mind that he'd be paying about $10 per month to rent it, and it's likely not as up to date or fully featured as one you can buy. That's why Leo recommends buying a separate router and modem. DOCSIS 3 or 3.1 should work. NetGear is recommended by TheWirecutter. Just make sure the gear is supported by the ISP, and call the ISP and they have to "ping it" and disable the rental gear.