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Catalyst 3560 Switch Software Configuration Guide
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Chapter 6 Clustering Switches
Understanding Switch Clusters
Cluster Command Switch Characteristics
A cluster command switch must meet these requirements:
It is running Cisco IOS Release 12.1(19)EA1 or later.
It has an IP address.
It has Cisco Discovery Protocol (CDP) version 2 enabled (the default).
It is not a command or cluster member switch of another cluster.
It is connected to the standby cluster command switches through the management VLAN and to the
cluster member switches through a common VLAN.
Standby Cluster Command Switch Characteristics
A standby cluster command switch must meet these requirements:
It is running Cisco IOS 12.1(19)EA1 or later.
It has an IP address.
It has CDP version 2 enabled.
It is connected to the command switch and to other standby command switches through its
management VLAN.
It is connected to all other cluster member switches (except the cluster command and standby
command switches) through a common VLAN.
It is redundantly connected to the cluster so that connectivity to cluster member switches is
maintained.
It is not a command or member switch of another cluster.
Note Standby cluster command switches must be the same type of switches as the cluster command
switch. For example, if the cluster command switch is a Catalyst 3560 switch, the standby
cluster command switches must also be Catalyst 3560 switches. Refer to the switch
configuration guide of other cluster-capable switches for their requirements on standby cluster
command switches.
Candidate Switch and Cluster Member Switch Characteristics
Candidate switches are cluster-capable switches that have not yet been added to a cluster. Cluster
member switches are switches that have actually been added to a switch cluster. Although not required,
a candidate or cluster member switch can have its own IP address and password (for related
considerations, see the “IP Addresses” section on page 6-13 and “Passwords” section on page 6-13).
To join a cluster, a candidate switch must meet these requirements:
It is running cluster-capable software.
It has CDP version 2 enabled.
It is not a command or cluster member switch of another cluster.