One of my IP cameras stopped working. It is PoE camera, so I restarted its port on my Cisco Catalyst 3750X switch, but that did not help. Looking at logs shown repeted error:

May  1 23:35:37.769: %ILPOWER-7-DETECT: Interface Gi1/0/6: Power Device detected: IEEE PD
May  1 23:35:38.775: %ILPOWER-5-POWER_GRANTED: Interface Gi1/0/6: Power granted
May  1 23:35:39.010: %ILPOWER-3-CONTROLLER_PORT_ERR: Controller port error, Interface Gi1/0/6: Power Controller reports power Imax error detected

May  1 23:35:49.756: %ILPOWER-7-DETECT: Interface Gi1/0/6: Power Device detected: IEEE PD
May  1 23:35:50.763: %ILPOWER-5-POWER_GRANTED: Interface Gi1/0/6: Power granted
May  1 23:36:18.764: %ILPOWER-3-CONTROLLER_PORT_ERR: Controller port error, Interface Gi1/0/6: Power Controller reports power Imax error detected

Solution to this by Cisco is to use... longer cable. Of course longer cable is not an option if you have all cables sealed in walls. One other option for extending cable is to add longer patchcord from patchpanel to switch if it is possible.

Seconf option is if you have most recent IOS to use command on problematic port:

power inline port 2x-mode

Complete configuration:

(config)#interface Gi1/0/6
(config-if)#power inline port 2x-mode
(config-if)#shutdown
(config-if)#no shutdown

After couple of seconds port came to life without any problem and camera started broadcasting.

May  1 23:51:06.908: %ILPOWER-7-DETECT: Interface Gi1/0/6: Power Device detected: IEEE PD
May  1 23:51:07.847: %ILPOWER-5-POWER_GRANTED: Interface Gi1/0/6: Power granted
May  1 23:51:08.275: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/6, changed state to down
May  1 23:51:11.303: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/6, changed state to up