Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
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Cisco IOS Release 12.2(25)SEC
• Other Considerations for Cluster Standby Groups, page 28
• Automatic Recovery of Cluster Configuration, page 29
• IP Addresses in Clusters, page 30
• Hostnames in Clusters, page 30
• Passwords in Clusters, page 31
• SNMP Community Strings in Clusters, page 31
• Switch Clusters and Switch Stacks, page 31
• TACACS+ and RADIUS in Clusters, page 33
• Availability of Switch-Specific Features in Switch Clusters, page 33
Cluster Compatibility
When creating a device cluster or adding a devices to a cluster, follow these guidelines:
• When you create a device cluster, we recommend configuring the highest-end device in your cluster
as the cluster command switch.
• If you are managing the cluster through Network Assistant, the device that has the latest software
should be the cluster command switch.
• The standby cluster command switch must be the same type as the command device. For example,
if the command device is a Cisco EtherSwitch service module, all standby command devices must
be either Cisco EtherSwitch service modules or Catalyst 3750 switches.
Command Device Characteristics
A command device must meet these requirements:
• It has an IP address.
• Clustering and the HTTP server are enabled (the default).
• CDP version 2 is enabled (the default).
• It is not a command device or a member in another cluster.
• It is connected to standby command devices through the management VLAN and to cluster members
through a common VLAN.
Standby Command Device Characteristics
A standby command device must meet these requirements:
• It has an IP address.
• It has CDP version 2 enabled.
• It is connected to the command device and to other standby command devices through its
management VLAN.
• It is connected to all other cluster members through a common VLAN.
• It is redundantly connected to the cluster so that connectivity to members is maintained.
• It is not a command device or a member in another cluster.
