Configuring Perpetual PoE and Fast POE

Restrictions for Perpetual and Fast PoE

The following restrictions apply to perpetual and fast PoE:

  • Configuration of Fast PoE or Perpetual PoE has to be done before physically connecting any endpoint. Alternatively do a manual shut/no-shut of the ports drawing power.

  • Power to the ports will be interrupted in case of MCU firmware upgrade and ports will be back up immediately after the upgrade.

  • When the switches are power-stacked, perpetual and fast PoE functionalities may not work as expected. This is due to power budget shortage.

  • The CREE light powered device (PD) may flap at regular intervals if not configured with IP assigned from the DHCP server.

  • If the PD does not support LLDP user can configure with either static or 2-event to receive required power as per the PD specification.

Information About Perpetual PoE

Perpetual PoE provides uninterrupted power to connected powered device even when a power sourcing equipment (PSE) switch is starting after a reload from executing the Cisco IOS software reload command.


Caution
Power to the ports will be interrupted in case of M3 or PSE firmware upgrade, and power to the ports will be backed up after Cisco IOS software starts.

Fast POE

Configuring Perpetual and Fast PoE

To configure perpetual and Fast PoE, perform the following steps.

Before you begin

Configure the perpetual-poe-ha command before connecting the powered device, or manually shut or unshut the port after configuring poe-ha command.

Procedure

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

Enter your password, if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

interface interface-id

Example:


Device(config)# interface gigabitethernet 2/0/1

Specifies the physical port to be configured, and enters interface configuration mode.

Step 4

power inline port perpetual-poe-ha

Example:


Device(config-if)# power inline port perpetual-poe-ha

Configures perpetual PoE. When you configure perpetual PoE on a port connected to a powered device, the powered device remains powered on during reload.

Step 5

power inline port poe-ha

Example:


Device(config-if)# power inline port poe-ha

Step 6

end

Example:


Device(config-if)# end

Returns to privileged EXEC mode.

Example: Configuring Perpetual and Fast PoE

This example shows how you can configure perpetual PoE on a switch:

Device> enable
Device# configure terminal
Device(config)# interface gigabitethernet2/0/1 
Device(config-if)# power inline port perpetual-poe-ha
Device(config-if)# end

Feature History for Perpetual PoE and Fast PoE

This table provides release and related information for the features explained in this module.

These features are available in all the releases subsequent to the one they were introduced in, unless noted otherwise.

Table 1. Feature History for Perpetual PoE and Fast PoE

Releases

Feature

Feature Information

Perpetual and Fast PoE

Perpetual PoE provides uninterrupted power to a connected powered device even when the PSE switch is booting.

Use the Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to Cisco Feature Navigator.