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How to Configure Power over Ethernet (PoE) interfaces on EX-series Switches

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Article ID: KB11239 KB Last Updated: 07 Aug 2020Version: 4.0
Summary:
Power over Ethernet is known by the acronym PoE and sometimes termed PoL (Power over LAN) or Inline Power. Power over Ethernet allows devices to transfer electrical power via Ethernet cable.

A network switch or computer can supply power to components such as VoIP phones, wireless LAN access points, and other appliances. With PoE, these external devices don’t need a separate power cord or outlet. PoE ports provide both network connectivity and electric power for the device connecting to the ports.
Solution:

EX-series switches provide PoE network ports with the various switch models providing either 8, 24, or 48 PoE ports. These ports can be used to connect VoIP telephones, wireless access points, video cameras, and point-of-sale devices to safely receive power from the same access ports that are used to connect personal computers to the network. To use a port in this manner, you must explicitly configure the port interface for PoE. When you configure a PoE interface, its ability to supply power to a connected powered device is enabled by default.

To configure PoE using the CLI:

  1. Enable PoE:

    • For all PoE interfaces:
      [edit]
      user@switch# set poe interface all
    • For a specific PoE interface:
      [edit]
      user@switch# set poe interface ge-0/0/0
  2. Set the power priority:

    • For all PoE interfaces:
      [edit]
      user@switch# set poe interface all priority low
    • For a specific PoE interface:
      [edit]
      user@switch# set poe interface ge-0/0/0 priority high
  3. Set the maximum PoE wattage available (the default is 15.4):

    • For all PoE interfaces:
      [edit]
      user@switch# set poe interface all maximum-power 14
    • For a specific PoE interface:
      [edit]
      user@switch# set poe interface ge-0/0/0 maximum power 12.8
  4. Enable logging of PoE power consumption with the default telemetries settings:

    • For all PoE interfaces:
      [edit]
      user@switch# set poe interface all telemetries
    • For a specific PoE interface:
      [edit]
      user@switch# set poe interface ge-0/0/0 telemetries
  5. Reserve a specified wattage of power for the switch in case of a spike in PoE consumption (the default is 0):

    [edit]
    user@switch# set poe guard-band 15

Verifying that the PoE Interfaces have been created with desired priorities:

Issue "show poe interface" command to display PoE interfaces. The show poe interface command lists PoE interfaces configured on the switch, with their status, priority, power consumption, and class. This command has been executed on a switch with partial PoE (8 PoE ports). The output shows that all eight PoE interfaces are enabled:

user@switch> show poe interface
Interface  Enabled  Status  Max-power Priority  Power-consumption  Class
ge-0/0/0   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/1   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/2   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/3   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/4   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/5   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/6   Enabled   ON       15.4W     Low        12.95W            0
ge-0/0/7   Enabled   ON       15.4W     Low        12.95W            0


Output Fields:

  • PoE Interface - Specifies the interface address.
  • Enabled - Specifies whether PoE capabilities are enabled or disabled.
  • Status - Specifies whether PoE is currently being provided to the port.
  • Max-power - Specifies the maximum power that can be provided to the port.
  • Priority - Specifies whether the port is high or low priority.
  • Power-consumption - Specifies how much power is being used by the port, as measured by the specified telemetries settings.
  • Class - Indicates the IEEE 802.af classification that defines the maximum power requirements for a powered device.


For an individual interface PoE details, issue  "show poe interface <interface-name>"  command:

user@host> show poe interface ge-0/0/3

PoE interface status:
PoE interface                               :  ge-0/0/3
PoE capability of the interface             :  Enabled    
Current status of power supply on interface :  OFF   
Power limit on the interface                :  12.0W      
Priority                                    :  High     
Power consumed                              :  0.0W              
Class of power device                       :  0
Modification History:
2020-08-06: Article reviewed for accuracy; no changes required.

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