[timewizard]

It doesn't require IPv6. The modem is just as aware of all the private IPv4 addresses on your network as well as all the public IPv6 ones.

Unless you put your own gateway (layer 3 switch, wifi ap, linux router) in front of it.

[Yeri]

From my understanding it tracks signal strength between two points (gateway and printer for example).

Putting your phone in airplane mode doesn't make it think you have left the house.

> If you’d like to prevent your pet’s movement from causing motion notifications, you can exclude pet motion in your WiFi Motion settings by turning on the Exclude Small Pets feature. > Motion is detected based on the amount of signal disruption taking place between the Xfinity Gateway and your selected WiFi-connected devices, so motion from small pets (around 40 pounds or less) can be filtered out while keeping you notified of large movements more likely to be caused by humans.

[frollogaston]

That would require Comcast to have access to your router, or more precisely, the NAT.

[nemomarx]

Comcast sells a router gateway combination device that's probably required for this motion sensing anyway. If you have that they could already check device counts and in fact their Xfinity app lists connected devices in detail.

[timewizard]

For most people their Comcast modem _is_ their router.

[frollogaston]

The point of the comment about ipv6 is that if you don't use a Comcast modem/router or they're prohibited by law from snooping on that, Comcast can still sorta understand the number of users from the outside by looking at your ipv6 addresses.

[timewizard]

I understand they can do traffic analytics but with privacy extensions and the proliferation of IoT devices I don't think that level of analysis is going to be very fine. Probably just enough to bin houses into different size groups.

There are a multitude of pre-existing ways of achieving the same result. One would be simply looking at the ft^2 listed on the public tax documents for the given address.

So I was really assuming any useful analysis would require them to be the actual man in the middle by owning and controlling your router. In which case address family does not matter.