Dell Force10 E600i FTOS Version 8.4.1.5 Configuration Guide for ExaScale - Page 741

Determine the Affect of a Port on the Power Budget The PoE power budget is affected differently depending on how PoE is enabled and whether a device is connected: 1. When you configure a port with power inline auto without the max_milliwatts power limit option, power is only allocated after you connect a device to the port. • When you connect a device, the maximum power for the device class is allocated if there is sufficient power in the budget. Refer to (Table 39-1). • If there is not enough power in the budget, the configuration is maintained and the port waits for power to become available. • If the device advertises its power requirement through LLDP-MED, then FTOS allocates the required amount and returns the remaining amount to the budget. Note: LLDP-MED TLVs are only honored if the port is configured with power inline auto (with or without the max_milliwatts option). 2. When you configure a port with power inline auto with the power limit option max_milliwatts, power is only allocated after you connect a device to the port. • If the maximum power for the device class is less than the power limit you specified, FTOS allocates the required amount and returns the remaining amount to the budget. • If there is not enough power in the budget, the configuration is maintained and the port waits for power to become available. • If the maximum power for the device class is more than the power limit you specified, FTOS does not allocate any power. Note: When a port is configured with power inline auto (with or without the max_milliwatts option) and the PoE device is disconnected, the allocated power is returned to the power budget. 3. When you configure a port with power inline static without the power limit option (max_milliwatts), FTOS allocates 15.4W (subject to availability and priority) to the port whether or not a device is connected. 4. When you configure a port with power inline static with the power limit option (max_milliwatts), FTOS allocates the specified number of Watts. • If there is not enough power in the budget, the configuration is maintained and port waits for power to become available. • If the maximum power for the device class is more than the power limit you specified, FTOS does not allocate any power. Power over Ethernet | 741