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Cisco IE 3010 Switch Software Configuration Guide
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Chapter 5 Clustering Switches
Planning a Switch Cluster
Note Catalyst 1900, Catalyst 2820, Catalyst 2900 XL, 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, Catalyst 3550, Catalyst 3560,
or Catalyst 3750 cluster command switch. Candidate and cluster member switches can
connect through any VLAN in common with the cluster comma nd switch.
Planning a Switch Cluster
Anticipating conflicts and compatibility issues is a high priority when you manage several switches
through a cluster. This section describes these guidelines, requirements, and caveats that you should
understand before you create the cluster:
• Automatic Discovery of Cluster Candidates and Members, page 5-4
• Virtual IP Addresses, page 5-9
• IP Addresses, page 5-11
• Hostnames, page 5-11
• Passwords, page 5-12
• SNMP Community Strings, page 5-12
• TACACS+ and RADIUS, page 5-12
• LRE Profiles, page 5-13
Refer to the release notes for the list of Catalyst switches eligible for switch clustering, including which
ones can be cluster command switches and which ones can only be cluster member switches, and for th e
required software versions and browser and Java plug-in configurations.

Automatic Discovery of Cluster Candidates and Members

The cluster command switch uses Cisco Discovery Protocol (CDP) to discover cluster member switches,
candidate switches, neighboring switch clusters, and edge devices across multiple VLANs an d in star or
cascaded topologies.
Note Do not disable CDP on the cluster command switch, on cluster members, or on any cluster-capable
switches that you might want a cluster command switch to discover. For more information about CDP,
see Chapter 25, “Configuring CDP.”
Following these connectivity guidelines ensures automatic discovery of the switch cluster, cluster
candidates, connected switch clusters, and neighboring e dge devices:
• Discovery Through CDP Hops, page 5-5
• Discovery Through Non-CDP-Capable and Noncluster-Capable Devices, page 5-6
• Discovery Through Different VLANs, page 5-6