Technical Documentation

Configuring PoE (CLI Procedure)

Power over Ethernet (PoE) ports supply electric power over the same ports that are used to connect network devices. These ports allow you to plug in devices that require both network connectivity and electric power, such as VoIP phones, wireless access points, and some IP cameras.

For EX Series switches that support PoE ports, the factory default configuration specifies and enables PoE interfaces for the PoE ports.

To configure PoE:

  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. By default the power management mode is static. To change the power management mode to class:

    [edit]
    user@switch# set poe management class

    Note: When the power management mode is set to class, the maximum power value is overridden by the maximum power value of the class of power device connected.

    Note: On a Juniper Networks EX2200 Ethernet Switch with 48 PoE ports, we recommend that you change the power management mode to class mode. On an EX2200 switch, the total power available to all PoE ports is 405 W. Under the default static mode settings, PoE power management reserves 15.4 W for each port, which means only 26 ports receive power. Given the default priority settings, the 26 ports that receive power are the first 26 ports.

    In class mode, on the other hand, the power provided to the port is determined entirely by the power demand of the device. Thus in class mode, any PoE port can be used to power a device and all 48 ports can be used as long as the combined power demand does not exceed 405 W.

  3. 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
  4. 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
  5. 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
  6. 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

Published: 2010-01-19