Getting non-advertising packets with nRF Sniffer?

[mwmccabe]

Hi, I would like to analyze data between a peripheral and a central (BLE 4.1.) It seems that the nRF52 and sniffer can only monitor advertising channels. Am I missing something?

[endnode]

nRF Sniffer can indeed follow the connection so what it is missing is probably CONNECT_REQ packet. Sometimes it happens because nRF Sniffer has only single radio on nRF5x DK board and while it tries to jump over all 3 channels to catch the CONNECT_REQ it cannot do magic. Also make sure that sniffer is in good position because again PCB antenna on nRF5x DK boards doesn't have properties of some more powerful and more expensive RF analyzers...

[mwmccabe]

Thank you for the reply. I've found a CONNECT_REQ packet, but how can I follow the connection?

[MartinBL]

Have you seen the user guide? infocenter.nordicsemi.com/.../sniffer_intro.html

It should be described there.

[mwmccabe]

I select the device but there are no packets being detected. I don't believe there is a passkey or a OOB. What few packets are detected aren't what I would expect, and are from the advertising channels... Could it be something with the way our BT protocol was structured?

[endnode]

Well debugging as usual:

1. Are you running the latest sniffer software, firmware and Wireshark? What nRF5x DK version you use to host sniffer FW?
2. Can you make it work withbother BLE devices as test set-up (whih you are sure run BT LE 4.0 or 4.1)?
3. If nothing helps can you attach few PCAP capture files and at leat one screenshot?

Using encrypted link shouldn't matter (but you might be missing PDU decoding) but using anonymous MAC might be a problem (never tried it).