Deauthentication is a wireless denial-of-service action that forces a Wi‑Fi client to disconnect from its access point. In practical terms, it interrupts the control messages that keep a device associated with a network, so the client drops off the air and must reconnect.
This matters in cyber security because deauthentication can be used to disrupt availability, trigger repeated reconnect attempts, or create a window for further attacks against wireless users. Attackers may send forged management frames, abuse weak wireless protections, or combine deauthentication with other tactics such as credential capture or traffic flooding. Defenders watch for unusual spikes in disconnects, repeated reassociation attempts, and rogue or malformed management frames. Stronger Wi‑Fi protections, monitoring for anomalous wireless behavior, and rapid isolation of suspicious access points help reduce the impact of this technique.