There is a "peer removed pairing information" error

[applesan]

I'm developing an app that communicates with iOS apps using Nordic's services.

I got this error during development. 

I have three questions about the "peer removed pairing information" error.

 1. Can this error occur due to a bug in the implementation of the app?

 2. Is there a way to intentionally reproduce and debug? 

 3. Is there anything the app can do to prevent this error from occurring?

 How to deal with it after it happened was discussed in other threads,

 but I would like to know if there is a way to avoid it.

Related threads: devzone.nordicsemi.com/.../bonded-phone-with-ios-13-4-unable-to-connect-to-the-nrf52-with-deleted-bonding-information

[Kenneth]

Typically bond handling is done by the OS, so I can't think that the app can control this. Are you using the latest iOS version? I guess the reason is as stated in this reply:
https://devzone.nordicsemi.com/f/nordic-q-a/60455/bonded-phone-with-ios-13-4-unable-to-connect-to-the-nrf52-with-deleted-bonding-information/246992#246992 

As a peripheral device it is possible to change the gap address, this will then make the peripheral device appear as a new device. You can find an example here on how this can be done:
https://devzone.nordicsemi.com/f/nordic-q-a/37369/switching-keyboard-mouse-between-3-paired-devices/143932#143932 

Kenneth

[applesan]

Thank you for your comment.

iOS is confirmed with the latest version.

Is changing the gap address a reproduction method?

In other words, is it possible to raise the same error by changing the gap address after connecting?

As a background, I think it is an error that has not occurred before, but it has occurred recently.

I would like to know if the error started to occur due to a problem with the implementation of the app,

or if the implementation of the app was irrelevant and it had occurred before.

Best regards,

kuma.

[Kenneth]

I consider your issue as working as intended. It is a security measure, to ensure that no attacker can fake/impersonate a bonded peer device. I assume it is intended that the user should delete previously bonded devices in iOS if the peer device have erased it's bond. The only way to avoid this would be if the peer device change the gap address, however this will leave the existing bond on iOS intact and instead create a new (it will thereby look like two peer devices have bonded to iOS).

Kenneth

[applesan]

I have a question.

Now that you know how to handle it on ios, why does the peer device erase the bond?

I would like to confirm whether it is a bug in the firmware implementation or a specification that occurs under specific conditions.

Best regards,

kuma.

[Kenneth]

applesan said:

Now that you know how to handle it on ios, why does the peer device erase the bond?

I am not sure what control you have of the peer device here, but many peers devices try to only have one active bond, so once the peer device bond to a new central device it will erase the previously bonded central device.

Kenneth

[applesan]

When this problem occurred, one iOS device and one peer device were in an active bond.

Suddenly the peer device got a "peer removed pairing information" error.

If so, did the peer device detect that something has changed in iOS and cause an error?

What changes in iOS will the peer device erase the bond?

kuma

[Kenneth]

Do you have an on-air sniffer log of the connection right before the issue occurs and when the issue occurs?

Kenneth