Each SSID that is present on an access point must have a unique MAC address (BSSID) so that clients can uniquely identify the network and communicate with the access point. As a consequence, when a new SSID is provisioned on the access point, a new MAC address must be created. To ensure that MAC address collisions do not occur, the access point typically uses its MAC address as a base address for newly generated SSIDs. Commonly, the last byte of the MAC address is incremented.
Procedure
- Identify a known valid SSID associated with the customer environment using your passive analysis tool.
- Record the BSSID (MAC address) for the selected access point to conduct searches.
- Remove the last byte of the MAC address and search for SSIDs that are potentially using the same access point hardware.
- Record any newly discovered SSIDs.
- Repeat on a sampling of different BSSIDs to ensure adequate coverage.