Frontier: if you don't buy your router, we'll charge you a rental fee; if you DO buy your router, we'll charge you a "support" fee

Are you running coax to multiple rooms and riding off that as your internal network?

To be clear (as far as I recall): all cable boxes that connect ethernet devices in your home to an external coax network have a MoCA bridge. It’s required for interconnecting the two types of hardware. But you can always establish a MoCA network in a house over coax run to each room. Super fast for folks who want to bother with that or need the internal speed, but wifi generally works well enough these days.