Contents

Configuring PoE· 1

Overview·· 1

PoE configuration task list 1

Enabling PoE· 2

Enabling PoE for a PSE· 2

Enabling PoE for a PI 2

Enabling nonstandard PD detection· 3

Configuring the maximum PI power 3

Configuring PI power management 4

Configuring PoE monitoring· 5

Configuring PSE power monitoring· 5

Configuring a PI by using a PoE profile· 5

Configuring a PoE profile· 6

Applying a PoE profile· 6

Upgrading PSE firmware in service· 6

Displaying and maintaining PoE· 7

PoE configuration example· 7

Troubleshooting PoE· 8

Failure to set the priority of a PI to critical 8

Failure to apply a PoE profile to a PI 9

 

Configuring PoE

Overview

IEEE 802.3af-compliant power over Ethernet (PoE) enables a network device to supply power to terminals over twisted pair cables.

As shown in Figure 1, a PoE system includes the following elements:

·     PoE power supply—The PoE power supply provides power for the entire PoE system.

·     PSE—A power sourcing equipment (PSE) detects and classifies powered devices (PDs), supplies power to PDs, and monitors the PD power and connection status. PSEs include endpoint PSEs and midspan PSEs.

H3C PSEs are endpoint PSEs. An H3C PSE can be a device with only one built-in PSE, or it can be a PoE-capable interface card or subcard on a device. A device with multiple PSEs uses PSE IDs to identify different PSEs. The display poe device command displays the mapping between a PSE ID and the slot or subslot number of a PSE.

·     PI—A power interface (PI) is a PoE-capable Ethernet interface on a PSE.

·     PD—A PD receives power from the PSE.

PDs include IP telephones, APs, portable chargers, POS terminals, and Web cameras.

You can also connect a PD to a redundant power source for reliability.

Figure 1 PoE system diagram

 

PoE configuration task list

You can configure a PI directly on the port or by configuring a PoE profile and applying the PoE profile to the PI. To configure one PI, configure it on the port. To configure multiple PIs in batches, use the PoE profile.

Before configuring PoE, make sure the PoE power supply and PSE are operating correctly. Otherwise, either you cannot configure PoE or the PoE configuration cannot take effect.

To configure PoE, perform the following tasks:

 

Tasks at a glance	Remarks
(Required.) Enabling PoE: ·     Enabling PoE for a PSE ·     Enabling PoE for a PI	N/A
(Optional.) Enabling nonstandard PD detection	N/A
(Optional.) Configuring the maximum PI power	N/A
(Optional.) Configuring PI power management	N/A
(Optional.) Configuring PSE power monitoring	N/A
(Optional.) Configuring a PI by using a PoE profile: ·     Configuring a PoE profile ·     Applying a PoE profile	N/A
(Optional.) Upgrading PSE firmware in service	N/A

 

Enabling PoE

This section describes how to enable PoE for a PSE and a PI.

Enabling PoE for a PSE

The system only supplies power to and reserves power for PoE-enabled PSEs.

You can enable PoE for a PSE if the PSE will not result in PoE power overload. PoE overload occurs when the sum of the power consumption of all PSEs exceeds the maximum power of PoE power supply. The maximum power of PoE power supply depends on the hardware specifications of the PoE power supply.

To enable PoE for a PSE:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enable PoE for the PSE.	poe enable pse pse-id	By default, this function is disabled.

 

Enabling PoE for a PI

The system only supplies power to and reserves power for PDs connected to PoE-enabled PIs.

You can enable PoE for a PI if the PI will not result in PSE power overload. PSE overload occurs when the sum of the power consumption of all PIs exceeds the maximum power of the PSE. The maximum PSE power is configurable.

If the PI will result in PSE power overload, you can enable PoE for the PI only when PI power management is enabled. For more information about PI power management, see "Configuring PI power management."

The PSE supplies power over the Category 3 or Category 5 twisted pair cable connected to a PI in the following modes:

·     Over signal wires—The PSE uses data pairs (pins 1, 2, 3, and 6) to supply DC power to PDs.

·     Over spare wires—The PSE uses spare pairs (pins 4, 5, 7, and 8) to supply DC power to PDs.

The switch series transmits power over signal wires.

 

	NOTE: A PSE can supply power to a PD directly only when the PSE and PD use the same power transmission mode. If the PSE and PD use different power transmission modes, you must change the order of the lines in the twisted pair cable to supply power to the PD.

 

To enable PoE for a PI:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter PI view.	interface interface-type interface-number	N/A
3.     Enable PoE for the PI.	poe enable	By default, PoE is disabled for a PI.
4.     (Optional.) Configure a description for the PD connected to the PI.	poe pd-description text	By default, no description is available for the PD connected to the PI.

 

Enabling nonstandard PD detection

By default, the PSE detects only IEEE 802.3af-compliant standard PDs and supplies power to them.

To enable nonstandard PD detection:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enable nonstandard PD detection.	poe legacy enable pse pse-id	By default, nonstandard PD detection is disabled.

 

Configuring the maximum PI power

The maximum PI power is the maximum power that a PI can provide to the connected PD. If the PD requires more power than the maximum PI power, the PI does not supply power to the PD.

A PSE uses LLDP to negotiate the PI power with a PD after you perform the following tasks:

·     Enable PoE and LLDP on the PSE.

·     Enable PoE and LLDP, and specify the dot3-tlv power keyword in the lldp tlv-enable command on the PI.

For more information about LLDP, see Layer 2—LAN Switching Configuration Guide.

To configure the maximum PI power:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter PI view.	interface interface-type interface-number	N/A
3.     Configure the maximum power for the PI.	poe max-power max-power	The default maximum PI power is 30000 milliwatts.

 

Configuring PI power management

PI power management enables the PSE to perform priority-based PI power management in PSE power overload situations. In descending order, the power-supply priority levels of a PI are critical, high, and low. The PD priority is determined by the priority of the PI to which the PD is connected. All PSEs use the same PI power management mechanism.

If you do not enable PI power management, the PSE might become overloaded. PSE power overload triggers the PoE self-protection mechanism to stop power supply to all PDs.

If you enable PI power management, the PSE stops power supply to existing PDs causing overload or performs priority-based operations for new PDs causing overload:

 

Priority of the new PD	PSE operations
Low	The PSE does not supply power to a new PD.
High	·     If low-priority PDs exist, the PSE stops power supply to the existing low-priority PDs, and supplies power to the new PD. ·     If no low-priority PDs exist, the PSE does not supply power to the new PD.
Critical	·     If low-priority or high-priority PDs exist, the PSE stops power supply to the existing low-priority or high-priority PDs, and supplies power to the new PD. ·     If no low-priority or high-priority PDs exist, the PSE does not supply power to the new PD.

 

	NOTE: Configuration for PIs whose power is preempted remains unchanged.

 

If multiple new PDs require power supply, the PSE supplies power to PDs in priority descending order. For PDs with the same priority, the one with the smallest PD ID takes precedence.

If multiple existing PDs need to be stopped with power supply, the PSE stops power supply to PDs in priority ascending order. For PDs with the same priority, the one with the greatest ID takes precedence.

The PSE guarantees its critical PIs uninterruptable power by reserving guaranteed PSE power. If you want a PI to be allocated with uninterruptable power, configure the PI with critical priority. Otherwise, configure the PI with high or low priority to ensure that other PIs can be supplied with power.

Before you configure a PI with critical priority, make sure the remaining guaranteed power is greater than or equal to the maximum power of the PI. The remaining guaranteed PSE power is the maximum PSE power minus the maximum power for PoE-enabled and PoE-disabled critical PIs.

To configure PI power management:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enable PI power management.	poe pd-policy priority	By default, PI power management is disabled.
3.     Enter PI view.	interface interface-type interface-number	N/A
4.     (Optional.) Configure the power supply priority for a PI.	poe priority { critical | high | low }	By default, the power supply priority for the PSE is low.

 

Configuring PoE monitoring

When the PoE monitoring function is enabled, the system monitors PSEs and PDs in real time. If a specific value exceeds the threshold, the system automatically takes self-protection measures.

If a PSE starts or stops power supply to a PD, the system automatically sends a notification message. For more information, see "Configuring SNMP."

Configuring PSE power monitoring

The system monitors PSE power utilization and sends notification messages when PSE power utilization exceeds or drops below the threshold. If PSE power utilization crosses the threshold multiple times in succession, the system sends notification messages only for the first crossing. For more information about the notification message, see "Configuring SNMP."

To configure a PSE power alarm threshold:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Configure a power alarm threshold for the PSE.	poe utilization-threshold utilization-threshold-value pse pse-id	By default, the power alarm threshold for the PSE is 80%.

 

Configuring a PI by using a PoE profile

A PoE profile is a collection of configurations that contain multiple PoE features.

You can configure a PI either on the port or by using a PoE profile. Follow these guidelines when you configure parameters for a PI:

·     The poe max-power max-power and poe priority { critical | high | low } commands must be configured in the same method.

·     If you configure a parameter twice with different methods, only the first configuration takes effect. To validate the second configuration, delete the first configuration.

The PoE profile is preferable for PI configuration in batches and PD-specific PI configuration.

·     You can apply a PoE profile to multiple PIs. PIs configured by the same PoE profile have the same PoE features.

·     You can define PoE configurations for a PD in a PoE profile, and apply the PoE profile to the PI to which the PD connects. This avoids reconfiguration when the PD is moved to another PI.

Configuring a PoE profile

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Create a PoE profile, and enter PoE profile view.	poe-profile profile-name [ index ]	N/A
3.     Enable PoE.	poe enable	By default, this function is disabled.
4.     (Optional.) Configure the maximum PI power.	poe max-power max-power	The default maximum PI power is 30000 milliwatts.
5.     (Optional.) Configure PI priority.	poe priority { critical | high | low }	The default priority is low.

 

Applying a PoE profile

You can apply a PoE profile in system view or PI view. If you perform the operation in both views, the most recent operation takes effect. To apply a PoE profile to multiple PIs, perform the operation in system view. If a PoE profile is applied, it cannot be deleted or modified before you remove its application.

A PoE profile can be applied to multiple PIs, but a PI can have only one PoE profile.

Applying a PoE profile to multiple PIs in system view

Step	Command
1.     Enter system view.	system-view
2.     Apply a PoE profile to one or multiple PIs.	apply poe-profile { index index | name profile-name } interface interface-range

 

Applying a PoE profile to a PI in PI view

Step	Command
1.     Enter system view.	system-view
2.     Enter PI view.	interface interface-type interface-number
3.     Apply the PoE profile to the interface.	apply poe-profile { index index | name profile-name }

 

Upgrading PSE firmware in service

You can upgrade the PSE firmware in service in either of the following modes:

·     Refresh mode—Updates the PSE firmware without deleting it. You can use the refresh mode in most cases.

·     Full mode—Deletes the current PSE firmware and reloads a new one. Use the full mode if the PSE firmware is damaged and you cannot execute any PoE commands.

If the PSE firmware upgrade fails because of interruption such as a device reboot, you can restart the device and upgrade it in full mode again. After the upgrade, restart the device manually for the new PSE firmware to take effect.

To upgrade the PSE firmware in service:

 

Step	Command
1.     Enter system view.	system-view
2.     Upgrade the PSE firmware in service.	poe update { full | refresh } filename [ pse pse-id ]

 

Displaying and maintaining PoE

Execute display commands in any view.

 

Task	Command
Display PSE information.	display poe device [ slot slot-number ]
Display the power supplying information for the specified PI.	display poe interface [ interface-type interface-number ]
Display power information for PIs.	display poe interface power [ interface-type interface-number ]
Display PSE information.	display poe pse [ pse-id ]
Display the power supplying information for all PIs on a PSE.	display poe pse pse-id interface
Display power information for all PIs on a PSE.	display poe pse pse-id interface power
Display all information about the PoE profile.	display poe-profile [ index index | name profile-name ]
Display all information about the PoE profile applied to the specified PI.	display poe-profile interface interface-type interface-number

 

PoE configuration example

Network requirements

As shown in Figure 2, configure PoE to meet the following requirements:

·     Enable the device to supply power to IP telephones and APs.

·     Enable the device to supply power to IP telephones first when overload occurs.

·     Allocate AP B a maximum power of 9000 milliwatts.

Figure 2 Network diagram

 

Configuration procedure

# Enable PoE for the PSE.

<PSE> system-view

[PSE] poe enable pse 1

# Enable PoE on GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, and GigabitEthernet 1/0/3, and configure their power supply priority as critical.

[PSE] interface gigabitethernet 1/0/1

[PSE-GigabitEthernet1/0/1] poe enable

[PSE-GigabitEthernet1/0/1] poe priority critical

[PSE-GigabitEthernet1/0/1] quit

[PSE] interface gigabitethernet 1/0/2

[PSE-GigabitEthernet1/0/2] poe enable

[PSE-GigabitEthernet1/0/2] poe priority critical

[PSE-GigabitEthernet1/0/2] quit

[PSE] interface gigabitethernet 1/0/3

[PSE-GigabitEthernet1/0/3] poe enable

[PSE-GigabitEthernet1/0/3] poe priority critical

[PSE-GigabitEthernet1/0/3] quit

# Enable PoE on GigabitEthernet 1/0/11 and GigabitEthernet 1/0/12, and configure the maximum power of GigabitEthernet 1/0/12 as 9000 milliwatts.

[PSE] interface gigabitethernet 1/0/11

[PSE-GigabitEthernet1/0/11] poe enable

[PSE-GigabitEthernet1/0/11] quit

[PSE] interface gigabitethernet 1/0/12

[PSE-GigabitEthernet1/0/12] poe enable

[PSE-GigabitEthernet1/0/12] poe max-power 9000

Verifying the configuration

# Connect the IP telephones and APs to the PSE to verify that they can obtain power and operate correctly. (Details not shown.)

Troubleshooting PoE

Failure to set the priority of a PI to critical

Symptom

Power supply priority configuration for a PI failed.

Analysis

Possible reasons include:

·     The guaranteed power remained for the PI is less than the maximum power required by the PI.

·     The priority of the PI is already set.

Solution

To resolve the problem:

·     In the first case, either increase the maximum PSE power or reduce the maximum power of the PI if the remaining guaranteed power of the PSE cannot be modified.

·     In the second case, remove the priority that is already configured.

Failure to apply a PoE profile to a PI

Symptom

PoE profile application for a PI failed.

Analysis

Possible reasons include:

·     Some configurations in the PoE profile are already configured.

·     Some configurations in the PoE profile do not meet the configuration requirements of the PI.

·     Another PoE profile is already applied to the PI.

Solution

To resolve the problem:

·     In the first case, remove the original configurations.

·     In the second case, modify the configurations in the PoE profile.

·     In the third case, remove the application of the undesired PoE profile from the PI.