What are the protocols used when logging in to facebook and using facebook messenger?
I read somewhere in google that the messenger uses MQTT protocol; How can I catch and analyze its related network packets in Wireshark?
The mobile application is using the MQTT protocol. The messenger on the webpage on the other hand, along with the login page communicate through a standard HTTPS protocol as the remaining part of the application.
You can sniff the HTTPS packets being sent on the local network, through wireshark but since HTTPS is SSL encrypted, you will just see hashes in the response body and you will not see the actual text. That's probably the main reason why you couldn't find it. In wireshark the HTTPS is denoted as SSLv3.