3Com Switch 7750 Configuration Guide Guide

662 CHAPTER 60: POE CONFIGURATION
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■ You can successfully enable PoE on a board only when the remaining power of
the switch is not less than the full power of this board.
■ The required power of PDs may exceed the power configured for them due to
their unstable status, thus causing the PDs connected to the last port on the
board to be powered off. Therefore, when you configure the maximum power
value for a board, ensure enough power for all ports of the board and reserve
additional 20 W power for instant high power at the same time.
■ Once PoE is enabled on a board, the system reserves the power for the slot
even after you remove the board from the slot; in this case, you can use the
undo poe enable slot command to release this power.
■ The reserved power for a blank slot will be recycled automatically by the system
if you insert a PoE-incapability board into the slot. The reserved power for a
blank slot will still be distributed to the slot if you insert a different type of
board into the slot and the board is PoE-enabled.
■ Before you enable the PoE-compatibility detection on a board, you must first
enable PoE on this board with the poe enable slot slot-num command.
■ When PoE-compatibility detection is performed on non-standard devices, the
system performance will be affected. When standard 802.3af devices are
connected to the board, you are not recommended to enable the
PoE-compatibility detection feature.
Setting the PoE Feature
of a PoE Port
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■ The Switch 7750 Family does not support the spare mode.
Tabl e 523 Set the PoE management mode and PoE priority of a port
Operation Command Description
Enter system view system-view -
Enter Ethernet port view
interface interface-type
interface-number
-
Enable the PoE feature poe enable
Required
By default, the PoE feature is
enabled on a port when the
PoE feature is enabled on a
board.
Set the maximum power
supplied by the port
poe max-power max-power
Optional
By default, the maximum
power supplied by the port is
15.4 W.
Set the power supply mode of
the port
poe mode { signal | spare }
Optional
The Switch 7750 Family
supports only the signal
mode.
Se the PoE priority of the port
poe priority { critical | high |
low }
Optional
By default, the PoE priority of
the port is low