PoE on HP Switches

Power over Ethernet (PoE) enables a power sourcing equipment (PSE) to supply power to powered devices (PDs).

To display the mapping between a PSE ID and the LPU (Line Processing Unit – “Slot”) of an interface card, execute the display poe device command.

The formula for calculating the PSE ID for a LPU is as follows:

  • In standalone mode – Slot number x 3 + 1.
    • For example, if the slot number is 3, the PSE ID is 3 x 3 + 1 = 10
  • In IRF mode – ((IRF member ID – 1) x 30 + Slot number) x 3 + 1.
    •  For example, if the chassis is 3 and the slot number is 4, the PSE ID is ((3 – 1) x 30 + 4) x 3 + 1 = 193.
[HP]disp poe device
PSE ID  SlotNo SubSNo PortNum  MaxPower(W)  State  Model
13      4      0      48       370          off    LSQ1GV48SD //PSE ID 13 refers to slot 4
22      7      0      48       370          off    LSQ1GV48SD //PSE ID 22 refers to slot 7
28      9      0      48       370          on     LSQ1GV48SD //PSE ID 28 refers to slot 9
34      11     0      48       370          on     LSQ1GV48SD //PSE ID 34 refers to slot 11
[HP]

Enabling PoE for a PSE (Required)

First, PoE must be enabled on each LPU:

[HP]poe enable pse 13
[HP]poe enable pse 22
[HP]poe enable pse 28
[HP]poe enable pse 34

Enabling the PSE to detect nonstandard PDs

Use it only for legacy devices that are pre-standard (known as “Cisco Inline Power”).

Current devices follow the standards defined in 802.3af (PoE, with a maximum of 15.4 W per port) or in 802.3at (PoE+, with a maximum of 25.5 W per port).

poe legacy enable pse pse-id

Configuring the maximum PoE power (Optional)

The PoE power supply of a device has its maximum output power (device maximum = M1), which is the hardware factor that determines the maximum PoE power.

PoE power supply has self-protection mechanism, with which hardware protection measures will be taken (for example, stopping power supply to all PSEs) in case of PoE power overload.

To avoid possible hardware protection, the device allows you to configure a maximum PoE power (M2, which should be lower than M1).

When the PoE power supply is to reach the overload state defined by M2, the system takes software protection measures (for example, disabling PoE of PSE or shutting down the power supply to PSE with a specific priority).

In this cases, the system re-allocates power according to power supply priority of PSEs.

A PSE with a higher priority gets power supply first. For the PSEs with the same priority, the one with a smaller PSE ID takes precedence.

To configure the maximum PoE power (in standalone mode):

poe power max-value max-power

Configuring the maximum PSE power (Required)

The maximum PSE power is the maximum power that the PSE can get from a PoE.

To avoid PSE power interruption due to PoE power overload, make sure the sum of power of all PSEs is less than the maximum PoE power.

The maximum power of the PSE must be greater than or equal to the sum of maximum power of all critical PoE interfaces on the PSE to guarantee the power supply to these PoE interfaces.

poe max-power 370 pse 13
poe max-power 370 pse 22
poe max-power 370 pse 28
poe max-power 370 pse 34

This configuration is always required because the default maximum power for the PSE is just 37 W, what’s not enough to power up a bunch of devices. So we increase this value to 370W or something higher.

To check the maximum PSE power that can be configured in a particular scenario, do the following:

[HP]poe max-power ?
INTEGER <37-806>  PSE maximum power

[HP]Poe max-power 806 pse 7 ?
<cr>

PoE power management

PoE power management involves PSE power management and PoE interface power management.

Configuring PSE power management

In a place where the maximum PoE power is insufficient to serve all PSEs, PSE power management is applied to decide whether to allow PSE to enable PoE, whether to supply power to a specific PSE and the power allocation method.

If PSE power management priority policy is enabled, the PSE with a lower priority is first disconnected to guarantee the power supply to the new PSE with a higher priority when the PoE power is overloaded.

The power supply priority levels of PSE are critical, high and low in descending order.

Configure a PSE power management priority policy:

poe pse-policy priority

Configure the power supply priority for the PSE:

poe priority { critical | high | low } pse pse-id

By default, low is the power supply priority for the PSE.

Configuring PoE interface power management

The power supply priority of a PD depends on the priority of the PoE interface.

The priority levels of PoE interfaces are critical, high and low in descending order.

If the PoE interface power management priority policy is enabled, the PD with a lower priority is first powered off to guarantee the power supply to the PD with a higher priority when the PSE power is overloaded.

Configure PoE interface power management priority policy:

poe pd-policy priority

Enter PoE interface view:

interface interface-type interface-number

Configure the power supply priority for a PoE interface:

poe priority { critical | high | low }

By default, low is the power supply priority for the interface.

Configuring PoE interface through PoE profile

You can configure a PoE interface by using a PoE profile and applying the PoE profile to the specified PoE interface.

Upgrading PSE processing software in service

poe update { full | refresh } filename pse pse-id

Displaying and maintaining PoE

Display PSE information (in standalone mode): display poe device

Display the power supply state of the specified PoE interface: display poe interface [ interface-type interface-number ]

Display power information for PoE interfaces: display poe interface power [ interface-type interface-number ]

Display power information for the PoE power supply and all PSEs (in standalone mode): display poe power-usage

Display PSE information: display poe pse [ pse-id ]

Display the power supply states of all PoE interfaces connected to the PSE: display poe pse pse-id interface

Display power information about all PoE interfaces connected to the PSE: display poe pse pse-id interface power

Display PoE power supply information (in standalone mode): display poe-power

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