【nRF Sniffer for Bluetooth LE】AUX_SCAN_REQ cannot be displayed on Wireshark

[xiaolongba]

Hello Nordic Experts,

Recently, I am using the nRF52840 dongle to sniff the Scannable Directed event, but I found that the AUX_SCAN_REQ cannot be sniffed, but the SCAN_REQ can be captured. can you give me a hand and check what happened？ the details as below::

• sniffer version: 4.1.0
• Wireshark: Version 3.6.2 (v3.6.2-0-g626020d9b3c3)

thanks.

[Vidar Berg]

Hello,

We don't have any examples that does extended scannable directed advertising, so I can't easily test this. Are you certain that the scanner actually sends the AUX_SCAN_REQ? Also, have you tried to select the device from the dropdown menu:

Best regards,

Vidar

[xiaolongba]

Hello Vidar Bro,

Many thanks for your prompt response. 

Vidar Berg said:

Are you certain that the scanner actually sends the AUX_SCAN_REQ?

yes, I can confirm that the scanner sends the AUX_SCAN_REQ as I tried to sniff the air packets with ellisys tool, the details as below:

also, the nRF connect app can also obtain the AUX_SCAN_RSP packets.

Vidar Berg said:

Also, have you tried to select the device from the dropdown menu

I cannot find the device from here, but the windows showed me that the device is present. also, I tried to restart again, the results are the same, the details as below:

thanks.

[Vidar Berg]

Hello,

Please try to restart the capture if the device is not showing up in the device list. One of the developers here confirmed that the sniffer will not wait for the AUX_SCAN_REQ if you have not selected which advertiser to track first.

Best regards,

Vidar

[xiaolongba]

Hello Vidar Bro,

yes, I tried to select the device from the dropdown menu after restarting several times, but I cannot find it from that, however, the device indeed is advertising. I can find it on the captured windows. it is very strange, but I can confirm that it works well when the event type change from scannable directed event to scannable undirected event.  it seems that it is a bug of nRF Bluetooth LE sniffer firmware, the device list may discard the device which is scannable directed event.

thanks.

[Vidar Berg]

Hello,

Do you have privacy enabled when you do directed advertising? In that case, you will need to provide the IRK as explained here: Sniffing advertisement packets involving a privacy-enabled Peripheral

[xiaolongba]

Hello Vidar Bro,

no, as you can see above, I am using the public address, not RPA, both of them are public type

also, as I said above, I only change the event type from scannable directed event to scannable undirected event.. the device can be found from the device list at this moment

[Vidar Berg]

Hello,

Ok, it's starting to look like a possible bug. I will try to set up a test here and see if I can reproduce the issue.

[xiaolongba]

Hello Vidar Bro,

OK, I am waiting for your good news.

thanks again.

[Vidar Berg]

Hello,

One of our developers confirmed that it is indeed a bug and created an internal task to investigate it further. I will keep you posted on the progress.