Administrator Guide

Power Allocation to Ports
When PoE/PoE+ is enabled, the power allocated to a port depends on how the PoE/PoE+ is enabled on the port and whether a device is
connected to the port.
• When you configure a port using the power inline command without setting the max_milliwatts power limit option, the Dell
Networking OS does not allocate any power to the port unless a device is connected and there is no limit to the amount of power
consumed by the powered device.
• When you configure a port using power inline with the max_milliwatts power limit option, the Dell Networking OS does not
allocate any power to the port unless a device is connected and restricts the maximum power consumed by the powered device to the
amount set in the max_milliwatts option.
• If the maximum power required for the connected device is less than the specified power limit, Dell Networking OS allocates the
required amount of power and returns the remaining power to the budget.
• If the maximum power required for the connected device is more than the specified power limit, Dell Networking OS does not allocate
any power.
• If there is no enough power in the budget, the configuration is maintained and the port waits till the required power is available.
• The max_milliwatts option has no effect on a port, when the port is configured in Class mode.
Power Allocation to Additional Ports
When additional ports are enabled with PoE/PoE+, the power is allocated based on the budget. The power budget is the amount of power
available from the installed PSUs minus the power required to operate the ports.
Use the show power inline and show power detail commands to determine if power is available for additional PoE ports. For
more information about these commands, see Dell Networking OS Command Line Reference Guide.
When you enable PoE/PoE+ on additional ports and the required power is more than the power supported by the budget, the power is
allocated as follows:
• If the newly PoE/PoE+ enabled port has a lower priority, then the command is accepted, but power is not allocated to the port. In this
case, the following message is displayed.
%Warning: Insufficient power to enable. POE oper-status set to OFF for port
• If the newly PoE/PoE+ -enabled port has a higher priority, then the command is accepted, and power is terminated on the lowest
priority port in the unit. If another power supply is added to the system at a later time, both the ports receive power.
• If all of the lower priority ports combined cannot meet the power requirements of the newly enabled port with high priority, then the
command is accepted, but power on the lower priority ports is not terminated, and no power is supplied to the port.
NOTE:
In the above scenario, even if a powered device is not connected to the port, the power is allocated. The
allocated power is deducted from the power budget and made unavailable to other ports.
Manage Legacy Devices
To detect and allocate inline power to the legacy devices on a stack unit, use the power inline legacy stack-unit unit-
number command in Configuration mode.
This command has the following parameters.
• stack-unitunit-number — Specify the stack unit number. The range is from 1 to 12.
Example:
Dell(conf)#power inline legacy stack-unit 1
Suspend Power Delivery on a Port
You can temporarily disable and then restore power on a port.
To disable inline power on a port, use the power inline suspend stack-unit unit number command in EXEC privilege mode.
When you use this command, the inline power to all the ports on the specified stack unit is disabled.
Power over Ethernet (PoE)
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