Cisco 3750G - Catalyst Integrated Wireless LAN Controller Configuration Manual page 125

Chapter 5 Managing Switch Stacks
A switch stack is different from a switch cluster. A switch cluster is a set of switches connected through
Note
their LAN ports, such as the 10/100/1000 ports. For more information about how switch stacks differ
from switch clusters, see the "Planning and Creating Clusters" chapter in the Getting Started with Cisco
Network Assistant, available on Cisco.com.
Switch Stack Membership
A switch stack has up to nine stack members connected through their StackWise ports. A switch stack
always has one stack master.
A standalone switch is a switch stack with one stack member that also operates as the stack master. You
can connect one standalone switch to another
containing two stack members, with one of them being the stack master. You can connect standalone
switches to an existing switch stack
If you replace a stack member with an identical model, the new switch functions with exactly the same
configuration as the replaced switch, assuming that the new switch is using the same member number as
the replaced switch. For information about the benefits of provisioning a switch stack, see the
Stack Offline Configuration" section on page
the "Troubleshooting" chapter in the hardware installation guide.
The operation of the switch stack continues uninterrupted during membership changes unless you
remove the stack master or you add powered-on standalone switches or switch stacks.
Make sure the switches that you add to or remove from the switch stack are powered off.
Note
After adding or removing stack members, make sure that the switch stack is operating at full bandwidth
(32 Gbps). Press the Mode button on a stack member until the Stack mode LED is on. The last two port
LEDs on all switches in the stack should be green. Depending on the switch model, the last two ports
are either 10/100/1000 ports or small form-factor pluggable (SFP) module ports. If, on any of the
switches, one or both of the last two port LEDs are not green, the stack is not operating at full bandwidth.
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For more information about cabling and powering switch stacks, see the "Switch Installation" chapter in
the hardware installation guide.
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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:
Power off the newly created switch stacks.
a.
Reconnect them to the original switch stack through their StackWise ports.
b.
Power on the switches.
c.
(Figure 5-1 on page
(Figure 5-2 on page 5-4) to increase the stack membership.
5-7. For information about replacing a failed switch, see
Catalyst 3750 Switch Software Configuration Guide
Understanding Switch Stacks
5-4) to create a switch stack
"Switch
5-3