How does a client find a wireless local area network (WLAN) during passive scanning?

The process of finding a wireless local area network (WLAN) during passive scanning primarily involves a client listening for beacon frames transmitted by access points (APs). These beacon frames contain important information, including the Service Set Identifier (SSID) of the network, which is the name that identifies the WLAN.

During passive scanning, the client does not actively transmit any requests or packets to discover nearby networks. Instead, it relies on the continuous broadcast of beacon frames by the APs. These frames are sent at regular intervals and provide the client with the necessary details to identify available networks, including their names and other parameters like supported data rates and security protocols.

Listening for beacons is an efficient way to gather information about the wireless environment without generating additional network traffic, which is why this method is utilized for passive scanning. Other methods, such as sending requests or analyzing encrypted packets, are not typical during passive scanning, as they involve active participation from the client rather than merely listening. Therefore, the focus on beacon frames and the SSID is key to understanding how clients find WLANs in this context.