Cluster Command Switch Characteristics; Standby Command Switch Characteristics; Chapter 6 Clustering Switche - Cisco Catalyst 2950 Software Configuration Manual

Understanding Switch Clusters
For more information about switch clustering, including cluster-planning considerations, see Getting
Started with Cisco Network Assistant, available on Cisco.com. For a 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 the required software versions, see the Release Notes for Cisco Network
Assistant, available on Cisco.com.

Cluster Command Switch Characteristics

A Catalyst 2950 or Catalyst 2955 command switch must meet these requirements:
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The CMP-NAT-ACL access list is created when a device is configured as the command switch.
Note
Configuring any other access list on the switch can restrict access to it and affect the discovery of
member and candidate switches.
We strongly recommend that the highest-end, command-capable switch in the cluster be the command
switch:
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Standby Command Switch Characteristics

A Catalyst 2950 or Catalyst 2955 standby command switch must meet these requirements:
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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
6-2
It is running Cisco IOS Release 12.0(5.2)WC(1) or later.
It has an IP address.
It has Cisco Discovery Protocol (CDP) Version 2 enabled (the default).
It is not a command or member switch of another cluster.
A Catalyst 2955 command switch is connected to the standby command switches through the
management VLAN and to the member switches through a common VLAN.
A Catalyst 2950 Long-Reach Ethernet (LRE) command switch is connected to the standby
command switches through the management VLAN and to the member switches through a common
VLAN.
If a non-LRE Catalyst 2950 command switch is running Cisco IOS Release 12.1(9)EA1 or later, it
is connected to the standby command switches through the management VLAN and to the member
switches through a common VLAN.
If a non-LRE Catalyst 2950 command switch is running a release earlier than Cisco IOS
Release 12.1(9)EA1, it is connected to the standby command switches and member switches
through its management VLAN.
If your switch cluster has a Catalyst 3550 switch, that switch should be the command switch.
If your switch cluster has Catalyst 2900 XL, Catalyst 2940, Catalyst 2950, Catalyst 2955, and
Catalyst 3500 XL switches, the Catalyst 2950 or the Catalyst 2955 should be the command switch.
It is running Cisco IOS Release 12.0(5.2)WC(1) or later.
It has an IP address.
It has CDP Version 2 enabled.
A Catalyst 2955 standby command switch is connected to other standby switches through its
management VLAN and to all member switches through a common VLAN.
Chapter 6 Clustering Switches
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