Planning A Switch Cluster - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 6 Clustering Switches

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:
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Refer to the release notes for the list of Catalyst switches eligible for switch clustering, including which
ones can be command switches and which ones can only be member switches, for the required software
versions, and for the browser and Java plug-in configurations.
Automatic Discovery of Cluster Candidates and Members
The command switch uses Cisco Discovery Protocol (CDP) to discover member switches, candidate
switches, neighboring switch clusters, and edge devices across multiple VLANs and in star or cascaded
topologies.
Note Do not disable CDP on the command switch, on cluster members, or on any cluster-capable switches that
you might want a command switch to discover. For more information about CDP, see
"Configuring CDP."
Following these connectivity guidelines ensures automatic discovery of the switch cluster, cluster
candidates, connected switch clusters, and neighboring edge devices:
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78-11194-09
Automatic Discovery of Cluster Candidates and Members, page 6-5
HSRP and Standby Command Switches, page 6-12
IP Addresses, page 6-16
Host Names, page 6-16
Passwords, page 6-16
SNMP Community Strings, page 6-17
TACACS+ and RADIUS, page 6-17
Access Modes in CMS, page 6-17
LRE Profiles, page 6-18
Availability of Switch-Specific Features in Switch Clusters, page 6-18
Discovery through CDP Hops, page 6-6
Discovery through Non-CDP-Capable and Noncluster-Capable Devices, page 6-6
Discovery through Different VLANs, page 6-7
Discovery through the Same Management VLAN, page 6-8
Discovery through Different Management VLANs, page 6-9
Discovery through Routed Ports, page 6-10
Discovery of Newly Installed Switches, page 6-11
Catalyst 3550 Multilayer Switch Software Configuration Guide
Planning a Switch Cluster
Chapter 22,
6-5