Join requests receive but not accept

While the join request is not encrypted, the AppKEY is used to generate its cryptographic checksum.

Since the device is using an AppKEY unknown to TTN, the message looks like a valid join request to the network server part of the infrastructure, but won’t validate as a join against an application to the join server function.

Essentially at the first level:

“that looks like a join request”

and at the second

“well, that’s not MY join request”

It all comes back to the correctly identified issue of the AppKEY needing to be a shared secret.

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