When the %CDP_PD-2-POWER_LOW: All radios disabled -LOW_POWER_CLASSIC inline power source platform=platform name> MAC address=xxxx.xxxx.xxxx> error message is received on the Cisco Access Point (AP), it indicates that the AP is in low power mode with all radios disabled. It also signifies that a Cisco switch that is unable to supply sufficient power to the AP has been detected.
In the Error message the <platform name> indicates the Cisco Discovery Protocol (CDP) device detected by the AP. The <xxxx.xxxx.xxxx> indicates the MAC address of the CDP device, typically, the switch port.
To resolve this issue a proper power source must be used. The AP can be powered from the 48-VDC power module or from an inline power source. The AP supports the IEEE 802.3af power standard, Cisco Pre-Standard PoE protocol, and Cisco Intelligent Power Management for inline power sources. For full operation, the AP requires 12.95 W of power. The power module and Cisco Aironet power injectors are able to provide the required power for full operation, but some inline power sources are not able to provide 12.95 W. Also, some high power inline power sources might not be able to provide 12.95 W of power to all ports at the same time. A Cisco power injector can be used to supply power to the AP. The MAC address of the switch port must be used when a power injector is configured to this port.
Eventhough a device is marked as 802.3af compliant the power output that each platform of devices can deliver varies with the devices. For example the Catalyst 3550-24-PWR provides 15.4 W per port at the switch output while the Catalyst 4000 family of switches can currently provide 6.3 W per port with the WS-X4148-RJ-45V line card. The following document has the information on the power options for the Cisco Aironet equipment and also provides information on the list of devices that support inline power and the power output in each case Cisco Aironet Power Over Ethernet Application Note