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Configuring Power over Ethernet in a Junos Fusion

 

PoE Configurable Options

Table 1 shows the configurable PoE options and their default settings in a Junos Fusion.

Some PoE options can be configured globally and per interface. In cases where a PoE interface setting is different from a global PoE setting, the PoE interface setting is configured on the interface.

Table 1: Configurable PoE Options and Default Settings

Option

Default

Description

disable (Power over Ethernet)

Not included in default configuration.

Note: PoE ports are disabled by default in a Junos Fusion.

Disables PoE on the interface if PoE was enabled. The interface maintains network connectivity but no longer supplies power to a connected powered device. Power is not allocated to the interface.

guard-band

0 W

Reserves a specified amount of power from the PoE power budget for possible spikes in PoE power consumption.

In a Junos Fusion, the guard band can be 0 to 19 W.

management

class

Sets the PoE power management mode for the extended port. The power management mode determines how power to a PoE extended port is allocated:

  • class—In this mode, the power allocated to a PoE extended port is determined by the class of the connected powered device. If there is no powered device connected, standard 15.4W power is allocated on the interface.

  • static—The maximum power delivered by an interface is statically configured and is independent of the class of the connected powered device. The maximum power is allocated to the interface even if a powered device is not connected.

maximum-power (Interface)

30.0 W (PoE+, IEEE 802.3at)

Sets the maximum power that can be delivered by a PoE interface when the power management mode is static.

In a Junos Fusion, all extended ports support PoE+ so the maximum power is up to 30 W.

This setting is ignored if the power management mode is class.

priority (Power over Ethernet)

low

Sets an interface’s power priority to either low or high. If power is insufficient for all PoE interfaces, the PoE power to low-priority interfaces is shut down before power to high-priority interfaces is shut down. Among interfaces that have the same assigned priority, the power priority is determined by port number, with lower-numbered ports having higher priority.

Enabling PoE

PoE is disabled by default for all extended ports in a Junos Fusion.

To enable PoE on all PoE-supported interfaces:

[edit]

user@aggregation-device# set poe interface all-extended

To enable PoE on a specific PoE-supported interface:

[edit]

user@aggregation-device# set poe interface interface-name

For instance, to enable PoE on extended port interface ge-100/0/24:

[edit]

user@aggregation-device# set poe interface ge-100/0/24

Disabling PoE

PoE is disabled by default in a Junos Fusion. Use this procedure to disable PoE in a Junos Fusion that has PoE previously enabled.

If PoE is enabled globally but disabled on a specific interface, PoE is disabled on the specified interface. This procedure can, therefore, be used to individually disable ports in cases where PoE is globally enabled.

If you want to disable PoE on all extended port interfaces in a Junos Fusion:

[edit]

user@aggregation-device# set poe interface all-extended disable

If you want to disable PoE on one extended port interface:

[edit]

user@aggregation-device# set poe interface interface-name disable

For instance, to disable PoE on extended port 101/0/1 in a Junos Fusion:

[edit]

user@aggregation-device# set poe interface 101/0/1 disable

If you want to enable PoE on all PoE-supported extended ports in a Junos Fusion except 101/0/10, enter the following commands:

[edit]

user@aggregation-device# set poe interface all-extendeduser@aggregation-device# set poe interface 101/0/10 disable

Setting the Power Management Mode

The power management mode in a Junos Fusion is set for all extended ports in a Junos Fusion .

The default power management mode is class.

To set the power management mode to static for all PoE extended ports:

[edit]

user@aggregation-device# set poe management static

To set the power management mode back to class for all PoE extended ports:

[edit]

user@aggregation-device# set poe management class

Setting the Maximum Power That Can Be Delivered from a PoE Interface

To set the maximum power that can be delivered to a connected device using PoE when the power management mode is set to static:

[edit]

user@aggregation-device# set poe interface interface-name maximum-power watts

To configure all extended port interfaces to the same maximum power, enter all-extended as the interface-name.

For instance, to change the maximum power for all PoE extended ports configured in static power management mode to 25 watts:

[edit]

user@aggregation-device# set poe interface all-extended maximum-power 25

To change the maximum power for interface 101/0/1 to 25 watts:

[edit]

user@aggregation-device# set poe interface 101/0/1 maximum-power 25

Setting the Guard Band

One guard band is configured for all extended ports in a Junos Fusion.

To set the guard band for all extended ports in a Junos Fusion:

[edit]

user@aggregation-device# set poe guard-band watts

For instance, to set the guard-band to 19 watts for all PoE extended ports:

[edit]

user@aggregation-device# set poe guard-band 19

Setting the PoE Interface Priority

To set a PoE interface priority to high:

[edit]

user@aggregation-device# set poe interface interface-name priority high

For instance, to assign a high priority to interface 101/0/1:

[edit]

user@aggregation-device# set poe interface 101/0/1 priority high

To set a PoE interface priority to low:

[edit]

user@aggregation-device# set poe interface interface-name priority low

For instance, to assign a low priority to interface 102/0/1:

[edit]

user@aggregation-device# set poe interface 102/0/1 priority low