3Com 4800G Series, Руководство по настройке

Страница: 1196 / 1246

1196 C
HAPTER
93: P
O
E C
ONFIGURATION
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CAUTION:
■
After a PoE configuration file is applied to a PoE interface, other PoE
configuration files can not take effect on this PoE interface.
■
If a PoE configuration file is already applied to a PoE interface, you must
execute the
undo apply poe-profile command to remove the application to
the interface before deleting or modifying the PoE configuration file.
■
If you have configured a PoE interface through the command line, you cannot
configure it through a PoE configuration file again. If you want to reconfigure
the interface through a PoE configuration file, you must first remove the
command line configuration on the PoE interface.
■
You must use the same mode (command line or PoE configuration file) to
configure the
poe max-power max-power and poe priority { critical | high |
low } commands.
Configuring PD Power
Management
The power priority of a PD depends on the priority of the PoE interface. The
priority levels of PoE interfaces include critical, high and low in descending order.
Power supply to a PD is subject to PD power management policies.
All PSEs implement the same PD power management policies. When the PSE
supplies power to a PD,
■
By default, no power will be supplied to a new PD if the PSE power is
overloaded.
■
Under the control of a priority policy, the PD with a lower priority is first
powered off to guarantee the power supply to the new PD with a higher
priority when the PSE power is overloaded.
n
If the sudden increase of the power of the PD results in PSE power overload,
power supply to the PD on the PoE interface with a lower priority will be stopped.
If the guaranteed remaining PSE power (power allocated to the critical PoE
interface subtracted from maximum PSE power, regardless of whether PoE is
enabled for the PoE interface) is lower than the maximum power of the PoE
interface, you will fail to set the priority of the PoE interface to
critical . Otherwise,
you can succeed in setting the priority to critical , and this PoE interface will
preempt the power of other PoE interfaces with a lower priority level. In the latter
case, the PoE interfaces whose power is preempted will be powered off, but their
configurations will remain unchanged. When you change the priority of a PoE
Apply the
PoE
configurati
on file to
the PoE
interface(s) Apply the PoE
configuration file to one
or more PoE interfaces apply poe-profile
{ index index | name
profile-name } interface
interface-range
Use either approach
Apply the PoE
configuration file to the
current PoE interface in
PoE interface view interface interface-type
interface-number
apply poe-profile
{ index index | name
profile-name }
To do… Use the command… Remarks