Specifications

7-5
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
78-11380-07
Chapter 7 Clustering Switches
Planning a Switch Cluster
Candidate Switch and Member Switch Characteristics
Candidate switches are cluster-capable switches that have not yet been added to a cluster. Member
switches are switches that have actually been added to a switch cluster. Although not required, a
candidate or member switch can have its own IP address and password (for related considerations, see
the “IP Addresses” section on page 7-16 and “Passwords” section on page 7-17).
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 member switch of another cluster.
• If the Catalyst 2955 member or candidate switch is running Release 12.1(12c)EA1 or later, it is
connected to the command switch through at least one common VLAN.
• If the Catalyst 2950 member or candidate switch is running Release 12.1(9)EA1 or later, it is
connected to the command switch through at least one common VLAN.
• If the Catalyst 2950 member or candidate switch is running a release earlier than
Release 12.1(9)EA1, it is connected to the command switch through the command-switch
management VLAN.
Note Catalyst 2950 standby command switches running Release 12.1(9)EA1 or later can connect to candidate
and member switches in VLANs different from their management VLANs. Catalyst 2955 standby
command switches running Release 12.1(12c)EA1 or later can connect to candidate and member
switches in VLANs different from their management VLANs.
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 7-6
• HSRP and Standby Command Switches, page 7-12
• IP Addresses, page 7-16
• Host Names, page 7-17
• Passwords, page 7-17
• SNMP Community Strings, page 7-17
• TACACS+ and RADIUS, page 7-18
• Access Modes in CMS, page 7-18
• Management VLAN, page 7-19
• LRE Profiles, page 7-19
• Availability of Switch-Specific Features in Switch Clusters, page 7-20
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, and for the required
software versions and browser and Java plug-in configurations.