A customer is evaluating device profiles on a CX 6300 switch.

The fallback role is used as a default role in the absence of a specified role or when an authentication server is not available. Given the scenario, where the test device with MAC address 81:cd:93:13:ab:31 needs to be assigned to "iot-prod" and other devices to "iot-default", and considering there is no external authentication server configured for the test, the appropriate action would be to set a global fallback role that applies to all devices connecting to the network. This ensures that any device that does not match the specific device profile will inherit the "iot-default" role. Since the configuration for a specific MAC address (81:cd:93:xx:xx:xx) to associate with the "iot-prod" role is already in place, setting the fallback role globally accommodates the requirement for other devices.