ble sniffer does not show fragmented L2CAP packets correctly

[Gilles Boccon-Gibod]

When using the sniffer to analyze GATT exchanges that use attributes > 20 bytes (which means L2CAP packets with fragmentation), the Wireshark tool does not show correct information. I only see the first L2CAP packet at the start of the connection event, and no other packets from the same connection event are shown. (When I do the same with "normal" GATT exchanges where the values are <= 20 bytes and therefore fit in a single packet, I can see the normal expected exchange). I don't even see the Empty PDU responses from the peripheral. Here's a screenshot of the Wireshark window: www.bok.net/.../Capture.PNG

I'm using the Adafruit nRF51822 USB sniffer, and ble-sniffer_win_1.0.1 I have tried with Wireshark 1.12 and 2.3.0, both show the same thing, so I'm guessing it is something wrong with the output of the USB dongle sniffer.

[Gilles Boccon-Gibod]

Yes, the BLE stack I'm using has its default MTU set at 240, and that setting is accepted by the macOS stack that I'm using on the Central side.