Cisco Systems 3750E Manual De Usuario
11-27
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02
Chapter 11 Configuring Interface Characteristics
Configuring Ethernet Interfaces
For information about the output of the show power inline user EXEC command, see the command
reference for this release. For more information about PoE-related commands, see the
reference for this release. For more information about PoE-related commands, see the
. For information about configuring voice
VLAN, see
Budgeting Power for Devices Connected to a PoE Port
When Cisco powered devices are connected to PoE ports, the switch uses Cisco Discovery Protocol
(CDP) to determine the CDP-specific power consumption of the devices, and the switch adjusts the
power budget accordingly. This does not apply to IEEE third-party powered devices. For these devices,
when the switch grants a power request, the switch adjusts the power budget according to the
powered-device IEEE classification. If the powered device is a class 0 (class status unknown) or a
class 3, the switch budgets 15,400 mW for the device, regardless of the CDP-specific amount of power
needed. If the powered device reports a higher class than its CDP-specific consumption or does not
support power classification (defaults to class 0), the switch can power fewer devices because it uses the
IEEE class information to track the global power budget.
(CDP) to determine the CDP-specific power consumption of the devices, and the switch adjusts the
power budget accordingly. This does not apply to IEEE third-party powered devices. For these devices,
when the switch grants a power request, the switch adjusts the power budget according to the
powered-device IEEE classification. If the powered device is a class 0 (class status unknown) or a
class 3, the switch budgets 15,400 mW for the device, regardless of the CDP-specific amount of power
needed. If the powered device reports a higher class than its CDP-specific consumption or does not
support power classification (defaults to class 0), the switch can power fewer devices because it uses the
IEEE class information to track the global power budget.
By using the power inline consumption wattage configuration command, you can override the default
power requirement specified by the IEEE classification. The difference between what is mandated by
the IEEE classification and what is actually needed by the device is reclaimed into the global power
budget for use by additional devices. You can then extend the switch power budget and use it more
effectively.
power requirement specified by the IEEE classification. The difference between what is mandated by
the IEEE classification and what is actually needed by the device is reclaimed into the global power
budget for use by additional devices. You can then extend the switch power budget and use it more
effectively.
Step 3
power inline {auto [max max-wattage] |
never | static [max max-wattage]}
never | static [max max-wattage]}
Configure the PoE mode on the port. The keywords have these meanings:
•
auto—Enable powered-device detection. If enough power is
available, automatically allocate power to the PoE port after device
detection. This is the default setting.
available, automatically allocate power to the PoE port after device
detection. This is the default setting.
•
(Optional) max max-wattage—Limit the power allowed on the port.
The range is 4000 to 15400 mW. If no value is specified, the
maximum is allowed (15400 mW).
The range is 4000 to 15400 mW. If no value is specified, the
maximum is allowed (15400 mW).
•
never—Disable device detection, and disable power to the port.
Note
If a port has a Cisco powered device connected to it, do not use
the power inline never command to configure the port. A false
link-up can occur, placing the port into the error-disabled state.
the power inline never command to configure the port. A false
link-up can occur, placing the port into the error-disabled state.
•
static—Enable powered-device detection. Pre-allocate (reserve)
power for a port before the switch discovers the powered device. The
switch reserves power for this port even when no device is connected
and guarantees that power will be provided upon device detection.
power for a port before the switch discovers the powered device. The
switch reserves power for this port even when no device is connected
and guarantees that power will be provided upon device detection.
The switch allocates power to a port configured in static mode before it
allocates power to a port configured in auto mode.
allocates power to a port configured in auto mode.
Step 4
end
Return to privileged EXEC mode.
Step 5
show power inline [interface-id |
module switch-number]
module switch-number]
Display PoE status for a switch or a switch stack, for the specified
interface, or for a specified stack member.
interface, or for a specified stack member.
The module switch-number keywords are supported only on
Catalyst 3750-E switches.
Catalyst 3750-E switches.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose