Configuring Power Management

The power management facility on EX6200 and EX8200 switches allows you to assign power priorities to the slots occupied by line cards. Power management provides power to the slots in priority order, which means that line cards in higher priority slots are more likely to receive power than line cards in lower priority slots if power to the switch is insufficient to power all the line cards.

The power priority you assign to a PoE line card affects both the order in which it receives base power and the order in which it receives PoE power. Base power is allocated first to all line cards in priority order. PoE power is then allocated to the PoE line cards in priority order.

When assigning power priority to slots, keep these points in mind:

• 0 is the highest priority. The number of priority levels depends on the number of slots in a switch—for example, for an EX8208 switch, which has eight slots, you can assign a priority of 0 through 7 to a slot.

• All slots are assigned the lowest priority by default.

• If a group of slots shares the same assigned priority, each slot’s power priority within the group is based on its slot number, with the lowest-numbered slots receiving power first. For example, if slot 3 and slot 7 each have an assigned power priority of 2, slot 3 has the higher power priority.

• On EX6200 switches, slots containing a Switch Fabric and Routing Engine (SRE) module are automatically assigned the highest priority. If you assign a priority of 0 to a slot that has a lower number than a slot an SRE module is in, the slot with an SRE module still receives power first. You cannot change the power priority of slot containing an SRE module.

By default, the power management feature in EX Series switches is configured to manage the power supplies for N+1 redundancy, in which one power supply is held in reserve for backup if any one of the other power supplies is removed or fails.

You can configure power management to manage the power supplies for N+N redundancy. For example, to set up your AC power supplies for dual power feed, N+N redundancy is required. In N+N redundancy, power management allocates half of the online power supplies to normal operating power and half to redundant power. If you have an odd number of online power supplies, power management allocates one more power supply to normal operating power than to redundant power.

This topic describes how to configure power management for N+N redundancy and how to revert back to N+1 redundancy if your deployment needs change.