I'm just a little confused - I listened to the video to help install the google wifi and they show the required equipment to install. From your information:
2) Please listen to the first 30 seconds which states that one of the google wifi units must be plugged into the modem/router.
Answered! Go to the Recommended Answer.
I'm just wondering why I need my modem - which casts wirelessly as well as the google wifi units? It appears I will be sitting two wireless units sitting together (the modem from Verizon and google) to cast wirelessly - this doesn't make sense?
It looks like Juzdu was able to give you some good info and help you out here. I just wanted to check up and see if you were all set. If you need anything else before I mark this as resolved, just let me know.
Google or Nest WiFi only replaces the LAN side, as Juzdu says you need a modem to form a bridge to your internet provider. Ideally log onto your Internet providers router, the admin password is usually on the card on the back, and turn off the wireless settings. Being a mesh system, your device (in theory) should automatically be connected to the strongest access point. If you leave the WiFi broadcast from your internet providers router, even if you broadcast the same SSID you will have to disconnect manually from the router to connect to the mesh. ie walking around with a phone, on the mesh you should be redirected to the strongest mesh point. If you are connected to your internet providers routers, your signal with just weaken.