Cisco Systems 3750E manual Creating a Switch Stack from Two Standalone Switches

Chapter 5 Managing Switch Stacks

Understanding Switch Stacks

Note Make sure that you power off the switches that you add to or remove from the switch stack.

After adding or removing stack members, make sure that the switch stack is operating at full bandwidth (64 Gb/s). Press the Mode button on a stack member until the Stack mode LED is on. The last two right port LEDs on all switches in the stack should be green. Depending on the switch model, the last two right ports are 10-Gigabit Ethernet ports or small form-factor pluggable (SFP) module ports (10/100/1000 ports). If one or both of these LEDs are not green on any of the switches, the stack is not operating at full bandwidth.

•Adding powered-on switches (merging) causes the stack masters of the merging switch stacks to elect a stack master from among themselves. The re-elected stack master retains its role and configuration and so do its stack members. All remaining switches, including the former stack masters, reload and join the switch stack as stack members. They change their stack member numbers to the lowest available numbers and use the stack configuration of the re-elected stack master.

•Removing powered-on stack members causes the switch stack to divide (partition) into two or more switch stacks, each with the same configuration. This can cause an IP address configuration conflict in your network. If you want the switch stacks to remain separate, change the IP address or addresses of the newly created switch stacks. If you did not intend to partition the switch stack:

a.Power off the switches in the newly created switch stacks.

b.Reconnect them to the original switch stack through their StackWise Plus ports.

c.Power on the switches.

For more information about cabling and powering switch stacks, see the “Switch Installation” chapter in the hardware installation guide.

Figure 5-1 Creating a Switch Stack from Two Standalone Switches

Stack member 1 Stack member 1

Stack member 1

Stack member 2 and stack master

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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