[sherry-sherry]

I don't think it's what's happening here, but iPhones absolutely communicate with each other when there's no cellular network.

The 'Find My' network uses all iPhones/iPads/Macs (unless disabled) to locate said devices and other items over Bluetooth LE.

> The Find My network is an encrypted, anonymous network of hundreds of millions of Apple devices that can help find your stuff, even when it’s offline. Nearby devices securely send the location of your missing device to iCloud, so you can find it in Find My. It’s all anonymous and encrypted to protect everyone’s privacy. — https://support.apple.com/en-au/104978

[MBCook]

But that’s just Bluetooth beacon stuff, it’s one way broadcast communication to anything that’s listening.

It’s like an automated ARP response packet that’s automatically transmitted occasionally without needing to hear a request.

[jlarocco]

Sure, but iOS has to listen for them and do... something... when they see a "Find my iPhone" beacon.

TBH I think it's very unlikely, but it's entirely possible they could add a flag to those beacon messages suggesting other iOS devices reboot.

On the other hand, I can easily see it being an honest bug where being off a cellular network corrupts the beacon message somehow, and reading the corrupt messages triggers iOS to reboot.

Who knows

[wobfan]

I don’t get why they’re suggesting that iPhone communicate to each other to reboot. I mean, what do the iPhone gain? Both have the system time and know for how long they have had no mobile network. They don’t have to set up complicated communication for that. What does the other device know more than the iPhone that makes it know that it has to restart?

[b112]

By some means, its location?

"HEY Bob, you're in the pokey, reboot so your filesystem is umounted!"

A network deprived phone might not realize, yet a friendly nearby may.

I doubt this is so, but it would be a fun game.

[therein]

Why could it not be something like Find My iPhone lock/reboot request is an encrypted packet that is destined to arrive at iPhone with Serial Number XYZ. Another iPhone gets near the target iPhone and shares its presence with Apple. Apple has been waiting to deliver this encrypted signed packet from Find My iPhone network to the target device. This packet is sent to the iPhone in range and then the data is delivered over AWDL.

[rfoo]

This breaks the anonymous nature of Find My network. There might be a way to mitigate it but I'm sure that's not a can of worm you would want to open.

[therein]

It is potentially more than just one-way Bluetooth beacon stuff. Apple tried to unify many ways Apple devices could communicate with each other over AWDL.

[mistrial9]

do you have evidence that it is only a beacon signal between Apple devices post v18 ?