You can configure the priority of a switch or powered device to receive power. This
priority determines the order in which devices are shut down in case of a power shortage.
You can configure three priorities per system: the system (or switch) priority, the
priority of the high-priority PoE ports on a switch, and the priority of the low-priority
PoE ports on a switch.
You set port priority at the interface level for powered devices connected to a PoE port. By default, all ports are low
You configure the priority values of each switch in the power stack and of all high and low
priority ports on that switch to set the order in which switches
and ports are shut down when power is lost and load shedding must occur. Priority values
are from 1 to 27; switches and ports with highest values are shut down first.
The 27 priorities are used to accommodate power stacks connected in a star configuration
with the expandable power supply. In this configuration, there would be nine members (switches)
per system with three priorities per switch.
On any switch, the switch priority must be lower than port priorities. and the high
priority value must be set lower than the low priority value. We recommend that you
configure different priority values for each switch and for its high priority ports and low
priority ports. This limits the number of devices shut down at one time during a loss of
power. If you try to configure the same priority value on different switches in a power
stack, the configuration is allowed, but you receive a warning message.
The default priority ranges, if none are configured, are 1-9 for switches, 10-18 for
high-priority ports, and 19-27 for low-priority ports.