What Is a BSSID?

A BSSID (Basic Service Set IDentifier) is the wireless equivalent of a MAC (Media Access Control) address, or a unique hardware address of an AP or VAP for the purposes of identification. Continuing the example of the roaming wireless client from the ESSID section above, as the client on the SonicWall ESSID moves away from AP1 and toward AP2, the strength of the signal from the former will decrease while the latter increases. The client’s wireless card and driver constantly monitors these levels, differentiating between the (V)APs by their BSSID. When the card/driver’s criteria for roaming are met, the client will detach from the BSSID of AP1 and attach to the BSSID or AP2, all the while remaining connected the SonicWall ESSID.