To prevent 802.11 sniffing and mitigate its effects, the following countermeasures can be employed:
Unlike wired sniffing (where you generally see traffic destined for your MAC address or broadcast traffic), 802.11 sniffing operates over the airwaves. To capture traffic effectively, you must understand the three primary modes of a Wireless Network Interface Card (WNIC):
If you are a network defender, sniffing your own network helps you:
802.11 sniffing, often called Wi-Fi sniffing or wireless packet analysis, is the process of capturing data packets traveling over a wireless local area network (WLAN). Unlike wired Ethernet networks, which transmit data through cables, 802.11 networks use radio frequencies (typically 2.4 GHz and 5 GHz). This makes their data inherently broadcast and, under the right conditions, accessible to anyone with a compatible receiver.
Sniffing 802.11 traffic that is not your own network, or for which you do not have explicit permission, is illegal in most jurisdictions under laws such as the Computer Fraud and Abuse Act (US) or the Computer Misuse Act (UK). Even capturing unencrypted management or probe frames can violate privacy laws.