Cisco Systems 3750E manual Passwords, Snmp Community Strings

Chapter 6 Clustering Switches

Planning a Switch Cluster

If a switch joins a cluster and it does not have a hostname, the cluster command switch appends a unique member number to its own hostname and assigns it sequentially as each switch joins the cluster. The number means the order in which the switch was added to the cluster. For example, a cluster command switch named eng-clustercould name the fifth cluster member eng-cluster-5.

If a switch has a hostname, it retains that name when it joins a cluster and when it leaves the cluster.

If a switch received its hostname from the cluster command switch, was removed from a cluster, was then added to a new cluster, and kept the same member number (such as 5), the switch overwrites the old hostname (such as eng-cluster-5) with the hostname of the cluster command switch in the new cluster (such as mkg-cluster-5). If the switch member number changes in the new cluster (such as 3), the switch retains the previous name (eng-cluster-5).

Passwords

You do not need to assign passwords to an individual switch if it will be a cluster member. When a switch joins a cluster, it inherits the command-switch password and retains it when it leaves the cluster. If no command-switch password is configured, the cluster member switch inherits a null password. Cluster member switches only inherit the command-switch password.

If you change the member-switch password to be different from the command-switch password and save the change, the switch is not manageable by the cluster command switch until you change the member-switch password to match the command-switch password. Rebooting the member switch does not revert the password back to the command-switch password. We recommend that you do not change the member-switch password after it joins a cluster.

For more information about passwords, see the “Preventing Unauthorized Access to Your Switch” section on page 9-1.

For password considerations specific to the Catalyst 1900 and Catalyst 2820 switches, see the installation and configuration guides for those switches.

SNMP Community Strings

Acluster member switch inherits the command-switch first read-only (RO) and read-write (RW) community strings with @esN appended to the community strings:

•command-switch-readonly-community-string@esN, where N is the member-switch number.

•command-switch-readwrite-community-string@esN, where N is the member-switch number.

If the cluster command switch has multiple read-only or read-write community strings, only the first read-only and read-write strings are propagated to the cluster member switch.

The switches support an unlimited number of community strings and string lengths. For more information about SNMP and community strings, see Chapter 33, “Configuring SNMP.”

For SNMP considerations specific to the Catalyst 1900 and Catalyst 2820 switches, see the installation and configuration guides specific to those switches.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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