Wireless packet capture has always been important to Wi-Fi professionals and support engineers for resolving network problems. With the diversity of wireless clients that is already around and which is only expected to grow with the Internet of Things (IoT), packet capture capabilities will continue to be critical. Wireless packet capture can be facilitated in the AP radios using the hardware and the driver level hooks. Read on to find out what’s under the hood.
There are two main plumbing points to get frames from wireless up to the application: one in the hardware and the other in the driver software. At the hardware level, the radio supports “Promiscuous Mode” option. When this option is activated, the hardware passes all wireless frames received on the channel where the radio is operating up towards the driver software. When this option is deactivated, the hardware passes only the wireless frames for the MAC of the radio (and the frames like probe requests & beacons based on the additional sub-settings under non-Promiscuous mode) up towards the driver software.
The driver software can operate in AP, STA, or Monitor Mode.