Cisco Catalyst 3560X-24P Command Reference Manual page 488

power inline police
3. The switch automatically sets the power usage of the device by using CDP power negotiation or by
the IEEE classification and LLPD power negotiation.
Use the first or second method in the previous list to manually configure the cutoff-power value by
entering the power inline consumption default wattage global configuration command, the power
inline consumption wattage interface configuration command, or the power inline [auto | static max]
max-wattage command.
If you do not manually configure the cutoff-power value, the switch automatically determines it by using
CDP power negotiation or the device IEEE classification and LLDP power negotiation. If CDP or LLDP
are not enabled, the default value of 30 W is applied. However without CDP or LLDP, the switch does
not allow devices to consume more than 15.4 W of power because values from 15400 to 30000 mW are
only allocated based on CDP or LLDP requests. If a powered device consumes more than 15.4 W without
CDP or LLDP negotiation, the device might be in violation of the maximum current (Imax) limitation
and might experience an Icut fault for drawing more current than the maximum. The port remains in the
fault state for a time before attempting to power on again. If the port continuously draws more than 15.4
W, the cycle repeats.
When a powered device connected to a PoE+ port restarts and sends a CDP or LLDP packet with a power
Note
TLV, the switch locks to the power-negotiation protocol of that first packet and does not respond to
power requests from the other protocol. For example, if the switch is locked to CDP, it does not provide
power to devices that send LLDP requests. If CDP is disabled after the switch has locked on it, the switch
does not respond to LLDP power requests and can no longer power on any accessories. In this case, you
should restart the powered device.
For more information about the cutoff power value, the power consumption values that the switch uses,
Note
and the actual power consumption value of the connected device, see the "Power Monitoring and Power
Policing" section in the "Configuring Interface Characteristics" chapter of the software configuration
guide for this release.
If power policing is enabled, the switch polices power usage by comparing the real-time power
consumption to the maximum power allocated on the PoE port. If the device uses more than the
maximum power allocation (or cutoff power) on the port, the switch either turns power off to the port,
or the switch generates a syslog message and updates the LEDs (the port LEDs are blinking amber) while
still providing power to the device.
To configure the switch to turn off power to the port and put the port in the error-disabled state, use
•
the power inline police interface configuration command.
• To configure the switch to generate a syslog message while still providing power to the device, use
the power inline police action log command.
If you do not enter the action log keywords, the default action is to shut down the port, turn off
power to it, and put the port in the PoE error-disabled state. To configure the PoE port to
automatically recover from the error-disabled state, use the errdisable detect cause inline-power
global configuration command to enable error-disabled detection for the PoE cause and the
errdisable recovery cause inline-power interval interval global configuration command to enable
the recovery timer for the PoE error-disabled cause.
Caution If policing is disabled, no action occurs when the powered device consumes more than the maximum
power allocation on the port, which could adversely affect the switch.
Catalyst 3750-X and 3560-X Switch Command Reference
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Chapter 2 Catalyst 3750-X and 3560-X Switch Cisco IOS Commands
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