The first device that I connect will work fine, reporting power consumption correctly.

Connecting a second or third device will seem to increase the power consumption on the first port while not reporting anything on any of those ports.

Furthermore, power output on these ports seems to switch on/off rapidly, creating a pulsating glow in the power led on those devices.

Troubleshooting done so far:

  1. Disconnected devices, reconnected on other ports. Result: same.
  2. Disconnected devices, connected devices in a different order. Result: the first port that is connected reports correctly, the subsequent ones doesn't not. (The difference is this time it is another device and another port.)
  3. Checked power consumption. Result: <7W pr port.

What am I doing wrong?

  • 3
    What is the Cisco switch model and software version?
    – YLearn
    Oct 29, 2014 at 19:01

2 Answers 2


It turned out to be an issue with gnd and negative being connected in the equipment in question.


Try this command in interface configuration mode:

(config-if)#power inline delay shutdown 20 initial 300

This command will give enough time for the device to power on and will not interrupt power during boot even if the device flaps link.

To execute this command for all interfaces at once use the range option of interface command an then:

(config-if-range)#power inline delay shutdown 20 initial 300

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