• PoE errors on the device seen on CLI.
• PoE devices connected to the device are not drawing power.
• PoE devices not listed as providing power.

The solution for troubleshooting a PoE issue includes trying the steps outlined below before concluding that the issue is due to configuration problems, interoperability issues, or physical defects that require the device to be RMA’ed.
 

• Firmware Errors – Check on the device if there are any firmware-related errors which need an upgrade.
• Troubleshoot Interop Issues – Ensure that the issue is not because of interoperability by trying any working PoE device on the same port.
• Configuration Issues – Troubleshoot and conclude that the configurations are accurate for the port to be providing PoE.
• Troubleshoot Junos Issues – Try this step to troubleshoot device issues before considering RMA'ing the device.
  • Check if the issue is due to power re-injection – Remove any connections where we expect the power to be injected into the device rather than receiving the power.

Firmware Errors

We expect to see below warning message when the device needs PoE firmware upgrade.

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)

If the output shows to upgrade POE firmware, DO NOT upgrade the PoE firmware unless instructed by JTAC


Troubleshoot Interop Issues

Test a known working PoE device on the port to verify proper functionality. If the device successfully provides power, adjust settings on the non-working peer end to resolve the issue.

Configuration Issues

First check the POE configuration for the interface which is not getting power:
{master:0}[edit poe]
user@switch# show
Interface all; <-- All interfaces are configured for POE or specific interface for which we are interested in troubleshooting.

Along with this ensure that the interface configurations are accurate in terms of speed, duplex, vlan settings and so on.

Troubleshoot Junos Issues
 
The “show poe controller” command shows 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

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

Example of working vs non-working outputs

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. To flap: “set interface x/x/x disable / enable”.

Additionally, we can also try flapping POE on the interface “set poe interface x/x/x disable / "delete poe interface x/x/x disable" (To enable the PoE interface again).

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

Also, we can try assigning 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 and additional troubleshooting performed earlier, then we could troubleshoot further with JTAC to get RMA.

Check if the issue is due to power re-injection
root@switch> show chassis alarms 
1 alarms currently active
Alarm time              Class Description
2023-12-14 11:16:30 IST Minor PoE voltage injection in Interface xx-x/x/x

The port reporting the alarm may not be the one that has injected the power. The reason is the POE controller provides the power to a group of ports. POE controller can go faulty depending on the voltage received on the port (Not necessarily the port showing alarm). If the switch port receive voltage of > 10W, it can damage the controller based on information from vendor. Many times, this issue is seen during the power maintenance or power outage since there may be power surge which may malfunction any device (Camera/AP’s etc) further leading to inject rouge voltage to the switches.

To solve the power injection problem:
 

• When the failure happens, configure a new switch with same configuration, code and install in parallel to existing switch.
• Remove the cables one by one from the existing switch and migrate to the new switch.
• While migrating the cables to the new switch, carefully observe for the alarm “PoE voltage injection in Interface” for all interfaces.
• While removing the connections from switch one by one, check if the alarm raised disappears at some point on problem switch or moved to the newer switch. Note down the end device and port triggered the alarm.
• If the alarm is still there then, with all the connections removed from the failed switch, power cycle/Hard reboot the problem switch. (Disconnect the power cable from the switch/outlet and connect it back)
• Once the switch is back after the hard reboot, check for the alarm. If the alarm disappears, connect all the connections back to the switch to check for the port reported PoE issue recovered.
• After hard reboot if the switch raises the alarm after reconnecting the devices, it means PoE controller detects the inject voltage again. Check for alarm and the triggered device after connecting which, the alarm was raised.
• If after removing all the connections and hard rebooting the switch did not recover the PoE, then this switch may have permanent failure.

Additional troubleshooting commands

Trace-options, which can also be enabled for troubleshooting:

• set syslog file messages any any
• set chassis traceoptions flag all
• set poe notification-control fpc <fpc-no>

Additional PoE troubleshooting commands

• show poe controller
• show poe interface
• show poe notification-control
• show poe telemetries interface x/x/x all (after enabling telemetrics)

2024-05-23: Command output added to Solution section along with traceoption details

2023-06-27: Update the instructions to not update PoE firmware unless instructed by JTAC

2020-06-20: Minor, non-technical update

7/17/2024 - evalle: Removal of QFX.