I’m replacing a gen1 ring base unit with a Ring pro. I have an all-in-one modem/router that I lease from our internet provider. I like it. It has great range and if something ever goes wrong with it, they have to fix it.
So can I use a Ring Pro base unit with my existing modem/router, without using the Ring Pro as the router? Basically I want to set it up just like the Gen1 Ring base unit where it just connects to my existing router.
The Alarm Pro Base Station is designed to be the primary router, or gateway, for your home. It should not be added to an existing wifi network. Check out our Help Center article below for a guide on setup and use.
Alternatively, the Ring Alarm Base Station is a also a choice, and can be added to an existing network. 
that’s my question…how can it simply be added to my existing network instead of making it my primary router
Hi @Kengull. I can go ahead a clarify here for Marley. The Gen 1 Ring Alarm Base Station, which you mentioned you already have, is what Marley was referring to here.
Since the Ring Alarm Pro is an Eero WiFi Router, it has to be setup as a Router. You don’t necessarily have to use the Router portion of the Ring Alarm Pro, but it does need to be setup.