I recently purchased a nest smoke alarm. My question is hopefully simple to answer.
The home icon is grey - does the smoke alarm need IVp6 to connect back to protect or can it connect using IVp4 or IVp6
A single Nest Protect can be setup without IPv6 support on your router. However, if you have more than one Nest Protect, IPv6 is necessary to establish the interconnect feature during pairing.
Google Nest Help Center
Chromecast Help Center