Sniffing Connection Data Packets

Question

Hi, 
 I am using my nRF52832 DK as a sniffer. 
 I am sniffing a BLE communication between a BLE door lock with a cellphone App. 
 I can see the device advertises continuously on on channels 37,38,39. 
 But, when i connect the App to the door lock and send lock/unlock commands (wich are seen by the lock movement), i can not see any MASTER->SLAVE or any form of connection commands. 
 Instead, I see the door lock keep advertising in channels 37,38,39. 
 I added a link to a sniffer capture - if required, i can provide more wireshark data. 
 /resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-3646d5b9449d4f018d82eb7b91950cfb/wireshark-capture1.png 
 Can you help me understand why am i not seeing data? 
 Thnaks.

Edvin · Accepted Answer

Hello, 
 When no devices are selected, only the advertising channels are scanned with the sniffer. If you are actually in a connection with the doorlock, or the doorlock supports severaln concurrent connections, and keeps advertising while it is in a connection. That very well be. If not, then it is not the doorlock's advertisement packets you are seeing, but something else. 
 
 Try to chose the doorlock in the dropdown menu: 
 
 Then the sniffer should follow the device into the connection, outside the advertising channels:

Best regards, Edvin