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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter6 Clustering Switches
Understanding Switch Clusters
Candidate Switch and Cluster Member Switch Characteristics
Candidate switches are cluster-capable switches and switch stacks that have not yet been added to a
cluster. Cluster member switches are switches and switch stacks 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 6-14 and “Passwords”
section on page 6-14).
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.
If a cluster standby group exists, it is connected to every standby cluster command switch through
at least one common VLAN. The VLAN to each standby cluster command switch can be different.
It is connected to the cluster command switch through at least one common VLAN.
Note Catalyst 1900, Catalyst 2820, Catalyst 2900XL, Catalyst 2950, and Catalyst 3500 XL
candidate and cluster member switches must be connected through their management VLAN
to the cluster command switch and standby cluster command switches. For complete
information about these switches in a switch-cluster environment, refer to the software
configuration guide for that specific switch.
This requirement does not apply if you have a Catalyst 2970, Catalyst3550, Catalyst 3560,
or Catalyst 3750 cluster command switch. Candidate and cluster member switches can
connect through any VLAN in common with the cluster command switch.