Cisco Systems 3560-X manual Planning a StackPower Stack Catalyst 3750-X Switches

Chapter 2 Switch Installation

Planning a StackPower Stack (Catalyst 3750-X Switches)

Figure 2-7 Example of a Partitioned Data Stack with a Failover Condition

STACK 1	STACK 2
1 STACK 1	STACK 2
2 STACK 1	STACK 2

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Power On Sequence for Switch Data Stacks

Consider these guidelines before you power on the switches in a stack:

•The sequence in which the switches are first powered on might affect the switch that becomes the stack master.

•If you want a particular switch to become the stack master, power on that switch first. This switch becomes the stack master and remains the stack master until a master re-election is required. After 1 minute, power on the other switches in the stack.

•If you have no preference as to which switch becomes the stack master, power on all the switches in the stack within 1 minute. These switches participate in the stack master election. Switches powered on after 1 minute do not participate in the election.

•Power off a switch before you add it to or remove it from an existing switch stack.

For conditions that can cause a stack master re-election or to manually elect the stack master, see the “Managing Switch Stacks” chapter in the switch software configuration guide on Cisco.com.

Planning a StackPower Stack (Catalyst 3750-X Switches)

Catalyst 3750-X switches can share power by using the StackPower feature.

•StackPower Stacking Guidelines, page 2-8

•StackPower Cabling Configurations, page 2-9

•Installing the Switch, page 2-14

StackPower Stacking Guidelines

You can configure a StackPower stack for either power sharing or redundancy. In power-sharing mode, the power of all the power supplies in the stack is aggregated and distributed among the stack members.

In redundant mode, when the total power budget of the stack is calculated, the wattage of the largest power supply is not included. That power is held in reserve and used to maintain power to switches and attached devices when one power supply fails. Following the failure of a power supply, the StackPower mode becomes power sharing.

Note Power-sharing mode is the recommended configuration for Catalyst 3750-X switches. The Catalyst 3560-X switches support only redundant mode.

Catalyst 3750-X and 3560-X Switch Hardware Installation Guide

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