Idle HomePod transmitting GBs of data daily

[Shamino (David C.)]

@david0

Wireshark also revealed a ton of IPv6 messages on my LAN. I really wasn’t expecting this. I surmise that all the Apple devices on my network (there are a lot) have all assigned themselves local IPv6 addresses, and use that address scheme to chat among themselves. I know very little about IPv6 (other than that it exists), so can’t really decipher the various IPv6 mcast messages that Wireshark captured. (My ISP does not support IPv6, and as far as I know, there is no DHCP server on my network assigning IPv6 addresses, so they must be self-generated by the Apple devices).

macOS has had IPv6 support for some time.

Whether or not your ISP provides support, every IPv6-capable device assigns itself a “link local” address (which all begin with fe80::. These addresses are automatically created by each device without any configuration or servers. Link local addresses are not routable and can therefore only be used on a single LAN segment, but they allow devices that are connected locally to communicate with each other without needing any configuration other than enabling IPv6 itself.

If your ISP supports IPv6, then you may have other (globally routable) IPv6 addresses in addition to the link-local addresses. These may come from an IPv6 DHCP server (maybe part of your router) or they may be auto-generated from the address block assigned by your ISP using IPv6’s Stateless Address Autoconfiguration protocol.

In terms of how to understand them, Wireshark should do all the ugly work decoding the packets. The IPv6 headers are different, but the layer-4 protocol (TCP, UDP, etc.) carried by it is the same.

[david0 (David C.)]

Thanks for the mini-tutorial on IPv6.

My ISP has not deployed IPv6 – they are years behind. Their infrastructure uses PPPoE, levering their legacy investment in DSL. But on the other hand, I get 500/500 Mbps over fibre.

[Shamino (David C.)]

Nothing wrong with DSL or PPPoE. These are so-called “layer 2” technologies. They transmit Ethernet-like data. Any layer-3 protocol (most commonly IPv4 and IPv6) can be in-turn layered on top.

As far as I know, Comcast/Xfinity is the only big player deploying IPv6 for residential broadband. But that doesn’t prevent computers on your LAN from using it for link-local communication, which Apple equipment generally does.

[ace (Adam Engst)]

@jzw

I’ve really enjoyed reading your journey of discovery, and have been following with bated breath. So thank you for keeping us updated, taking the time to investigate, and posting all the details here.

Very much agreed—thanks, @david0! A great boon to everyone here.

[gib]

Charter/Spectrum supports IPv6 rather well, at least in Birmingham. My primary DNS is IPv6, with the second being an IPv4 server,third IPv6, and fourth IPv4. And IPv6 is definitely the future; all Internet of Things stuff is headed that way, with the consortium of Apple, Google, Zigbee, and Amazon to use a single interface (Connectivity Standards Alliance [CSA],formerly known as the Zigbee Alliance), which will be based on IPv6. It’s time to learn about it; IPv4 is going the way of the white rhino!