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[EX] Power over Ethernet (PoE) switch troubleshooting

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Article ID: KB31533 KB Last Updated: 20 Jun 2020Version: 2.0
Summary:

This article explains how to troubleshoot Power over Ethernet (PoE) related issues.

Symptoms:

PoE device not getting power from EX switch.

Solution:
  • Check the POE configuration for the interface which is not getting power:
    {master:0}[edit poe]
    user@switch# show
    Interface all; <-- All interfaces are configure for POE
     
  • Check the output, “show poe controller”. This output will show the power consumption of the POE devices.

    user@switch> show poe controller
    Controller  Maximum   Power         Guard    Management  Status   Lldp
    index       power     consumption   band                          Priority
       0**      130.00W     2.28W           0W     Class      AF_MODE  Disabled

    ‚ÄčThe above output shows that switch is providing power to end device and consumption is 2.28W.

  • If the output shows to upgrade POE firmware, proceed with an upgrade of POE firmware.

    user@switch> show poe controller
    Controller Maximum   Power         Guard    Management   Status        Lldp
    index       power     consumption   band                                Priority
       0**      130.00W   2.28W           0W     Class        AF_MODE       Disabled
      **New PoE software upgrade available.
    Use 'request system firmware upgrade poe fpc-slot <slot>' 
    This procedure will take around 10 minutes (recommended to be performed during maintenance)
    Use the following command to upgrade the PoE firmware:

    request system firmware upgrade poe fpc-slot <slot>

    Note: JTAC recommends to upgrade POE firmware during maintenance window.
  • Check the POE enabled interface using “show poe interfaces” :


Working scenario output:

user@switch> show poe interface
Interface    Admin       Oper    Max        Priority       Power          Class
             status      status  power                     consumption
 ge-0/0/4    Enabled      ON     15.4W      Low            2.3W            3
 

Non-working scenario Output:

user@switch> show poe interface
Interface    Admin       Oper    Max        Priority       Power          Class
             status      status  power                     consumption
ge-0/0/0    Enabled     OFF     15.4W      Low            0.0W          not-applicable

 

  • Check the interface operational status where POE devices are connected.

    user@switch> show poe interface ge-0/0/0
    PoE interface status:
    PoE interface                :  ge-0/0/0
    Administrative status        : Enabled <-- POE is enabled
    Operational status           : OFF <-- This shows POE is enabled but no power supplied.
    Power limit on the interface : 15.4W
    Priority                     : Low
    Power consumed               : 0.0W
    Class of power device        : not-applicable
    PoE Mode                     :  802.3af
     
  • If the operational status shows OFF, flap the interface and check the status if the device is consuming the power or not.

  • Check for power consumption history for that particular POE interface:

    user@switch> show poe telemetries interface ge-0/0/4
    Sl No    Timestamp                Power    Voltage
       1     01-21-2010 19:51:00 UTC  2.3W     50.6V
       2     01-21-2010 19:50:00 UTC  2.3W     50.6V
       3     01-21-2010 19:49:00 UTC  2.4W     50.7V
       4     01-21-2010 19:21:00 UTC  0.0W     50.8V
       5     01-21-2010 19:20:00 UTC  0.0W     50.7V
  • Assign static power to the PoE interface and check the status (set the maximum PoE wattage available i.e 15.4W)

    user@switch# set poe interface <interface-name> maximum-power <power in watts>

  • If switch will not provide power after configuring static power, then please open a case with JTAC.
Modification History:
2020-06-20: Minor, non-technical update.
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