Monitoring Wi-Fi Traffic with ESP32

Probe requests are Wi-Fi signals sent by devices seeking network availability. These 802.11 management frames enable devices to discover and connect to nearby wireless networks efficiently.

The ESP32 is a versatile microcontroller with integrated Wi-Fi. It can monitor wireless traffic, including probe requests, through its 'promiscuous' or 'sniffer' mode, allowing deep network inspection.

To monitor probe requests, configure the ESP32 in promiscuous mode using the 'esp_wifi_set_promiscuous' function. This taps into Wi-Fi packet metadata without connecting to a network.

While in promiscuous mode, ESP32 can capture probe requests with a callback function. The function logs the sender's MAC address, signal strength, and sometimes the SSID.

Captured data can reveal patterns such as device presence, movement, and preferred networks. With careful analysis, it's possible to infer behavioral patterns or network preferences.

Monitoring probe requests raises privacy concerns. Ethical considerations should guide the use of this technology, ensuring compliance with privacy laws and respect for individual consent.

Beyond basic monitoring, ESP32 can be programmed for tasks like Wi-Fi deauthentication detection, creating makeshift Wi-Fi 'intrusion detection systems' to enhance network security.