power-over-ethernet power-pairs

power-over-ethernet power-pairs {alt-a | alt-a-and-alt-b}

no power-over-ethernet power-pairs {alt-a | alt-a-and-alt-b}

Description

Configures the four-pair capable switch to operate in a mode, that restricts the power delivery for class 0 to class 4 single signature devices to operate only on ALT-A power pair.

When configured, a warning message is displayed. User must accept the warning by entering Y to enable the mode.

The no form of this command resets the power pairs to default PoE pairs.

Parameter

Description

alt-a

Delivers power only on the ALT-A pair.

alt-a-and-alt-b

Delivers power on the ALT-A and ALT-B pairs. This is the default configuration on all PoE interfaces.

Usage

IEEE 802.3bt devices such as four-pair (class 5 and higher) and dual signature powered devices require power on both pairs. However, there is no such restriction on IEEE 802.3af (class 0 to class 3) and IEEE 802.3at (class 4) powered devices not to draw power on both pairs if the overall consumption does not violate the power class limit. For such powered devices, a power-pairs configuration is provided to configure the 4-pair capable switch to restrict power on only one power pair.

Examples

Configuring PoE power pairs:

switch(config)# interface 1/1/1 switch(config-if)# power-over-ethernet power-pairs alt-a This setting configures the interface to deliver power only on the ALT-A cable pair when a Class 0-4 device is connected. Devices that require power on all pairs may not operate correctly. Continue (y/n)? y

Resetting the PoE power pair to default:

switch(config-if)# no power-over-ethernet power-pairs alt-a This setting configures the interface to deliver power on the ALT-A and ALT-B cable pairs. This is the default and most devices work properly with this setting, however some older Class 0-4 devices may not operate correctly. Continue (y/n)? y

Command History

Release

Modification

10.09

Command Introduced

Command Information

Platforms

Command context

Authority

6300

6400

config-if

Administrators or local user group members with execution rights for this command.