Allocation of PoE Power to Modules

The switch firmware determines the power available for PoE based on hardware configuration, power supply status, and power supply redundancy mode. The system calculates and reserves the correct amount of power required by the installed hardware components and then makes the balance of power available for PoE. When any change is made to the hardware configuration, power supply status, or redundancy mode, the firmware recalculates the power available for PoE.

On the S- K- and 7100-Series switch, you can manually configure the maximum percentage of PoE power available to the chassis as a percentage of the total installed PoE power with the set inlinepower available command. If the power needed or requested exceeds the power available, the system will generate a trap to notify the system manager, if traps are enabled.

The power available for PoE is distributed based on the configured allocation mode, set with the set inlinepower mode command:

• Automatic mode, in which available power is distributed evenly to PoE-capable modules based on PoE port count. (This is the default mode.) Any change in available power, due to a change in power supply status or redundancy mode or to the addition or removal of modules, will trigger an automatic redistribution of power.
• Manual mode, in which the power budget for each PoE-capable module is manually configured, using either CLI commands or the MIBs. The sum of the wattage configured for each module cannot exceed the total power available on the switch for PoE.

  The power budget for each PoE-capable module can be configured manually on the S- K- and 7100-Series switch with the command set inlinepower assigned.

  The configured wattage assignments are used to calculate each slot‘s percentage of total available power. If the total available PoE power is reduced, a redistribution of available power will occur, applying the calculated percentages.