UDP packet from RIOT OS sent with "udp send fe80::3033:82b1:a9a0:928d 32323 test" :

Data - Time[2018-11-29 08:52:25.986163] Addresses[Destination[PAN[23] ExtAddr[323382b1a9a0928d]] Source[PAN[23] ExtAddr[6e177429030a9216]]] MSDU[7e33f07e437e43b9ff74657374eee7] RssiSniff[-91]

UDP packet from Linux sent with my Python script from first mail :

Data - Time[2018-11-29 08:53:34.689118] Addresses[Destination[PAN[23] ShortAddr[ffff]] Source[PAN[23] ExtAddr[323382b1a9a0928d]]] MSDU[7b393a0201ff159202870094f800000000fe800000000000006c17742f031592020102323382b1a9a0928d0000000000001eeb] RssiSniff[-43]