The AP Fails to Be Powered On by PoE

General Troubleshooting Procedure

1. Check whether the PSE and AP comply with PoE standards.
   1. Determine the PoE standards supported by the AP.
   2. Determine the PoE standards supported by the PSE. The following method applies only to Huawei PoE switches. Run the display poe power command in the system view.

      <Switch> display poe power
      Codes: REFPW(Reference power), USMPW(User set max power),
             CURPW(Current power), PKPW(Peak power), AVGPW(Average power)
      
      PortName               Class  REFPW(mW) USMPW(mW) CURPW(mW) PKPW(mW)  AVGPW(mW) 
      ------------------------------------------------------------------------------
      GigabitEthernet0/0/1   -      -         30000     0         0         0   

      Check the value of the USMPW field.

      • The value 15400 indicates that the switch supports IEEE 802.3af.
      • The value 30000 indicates that the switch supports IEEE 802.3at.

      Check whether the switch and AP comply with the same PoE standards. If not, replace the switch with a PoE switch in compliance with the same PoE standard as the AP.

2. Check whether the switch is properly grounded.

   Check whether the switch shell is properly grounded.

3. Check whether the PoE function is enabled on the switch.

   The following method applies only to Huawei PoE switches.

   Run the following command in the system view (GE0/0/3 is used as an example):

   [Switch] display poe power-state interface gigabitEthernet 0/0/3 
    Port legacy detect           : disable 
    Port power enabled           : Disable 
    Port power ON/OFF            : off

   If the Port power enabledfield isDisable in the command output, enable the PoE function in the interface view.

   <Switch> system-view 
   Enter system view, return user view with Ctrl+Z. 
   [Switch] interface GigabitEthernet 0/0/3 
   [Switch-GigabitEthernet0/0/3] poe enable 
   [Switch-GigabitEthernet0/0/3] quit 
   [Switch] quit

4. Check whether the remaining power of the switch is sufficient.

   The following method applies only to Huawei PoE switches.

   Run the display poe information command in the system view.

   <Switch> display poe information
   PSE Information of slot 0:
   User Set Max Power(mW): 739200
   POE Power Supply(mW)       : 369600
   Available Total Power(mW)   : 369600
   Total Power Consumption(mW) : 0
   Power Peak Value(mW)       : 0
   Power-Management Mode      : auto
   Power High Inrush          : disable

   Check whether the value of the Available Total Power field meets the AP power requirement.

   Table 5-1 AP power requirement

   AP PoE Standards	Available Total Power
   IEEE 802.3af/at	≤ 15400 W
   IEEE 802.3af	≤ 15400 W
   IEEE 802.3at	≤ 30000 W
   IEEE 802.3bt	≤ 90000

   If the value of the Available Total Power field is smaller than the required AP power, increase the power of the switch or power off idle PDs.

5. Check whether the network cables comply with PoE standards.

   A network cable tester or multimeter is used to check network cable quality.

   Table 5-2 Network cable quality required by PoE standards

   Standard		Total Resistance of a Network Cable
   802.3af		≤ 20 ohms
   802.3at	Type1	≤ 20 ohms
   	Type2	≤ 12.5 ohms
   802.3bt		≤ 12.5 ohms

   The resistance of a network cable can be tested using the following methods:

   • Method 1

     Use a network cable tester to test the resistance of a network cable.

   • Method 2

     Connect test probes of a multimeter to the two ends of each network cable, and read the resistance value of the network cable on the multimeter. The cable resistance approximately equals the displayed value.

   • Method 3

     Connect a network cable to an AP. Use a multimeter to test the resistance between pins 1 and 2 of the cable (or between pins 3 and 6, 4 and 5, or 7 and 8). The cable resistance approximately equals half of the displayed value.

   If the resistance of a network cable does not meet requirements of PoE standards, replace the network cable.