Cisco IE 4000, Software Configuration Manual

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Configuring Switch Clusters
How to Plan for Switch Clustering
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 Prevention for Unauthorized Switch Access, page 143 .
For password considerations specific to the Catalyst 1900 and Catalyst 2820 switches, refer to the installation and
configuration guides for those switches.
SNMP Community Strings
A cluster 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
Configuring SNMP, page 527
For SNMP considerations specific to the Catalyst 1900 and Catalyst 2820 switches, refer to the installation and
configuration guides specific to those switches.
and RADIUS
If is configured on a cluster member, it must be configured on all cluster members. Similarly, if RADIUS is
configured on a cluster member, it must be configured on all cluster members.The same switch cluster cannot have some
members configured with and other members configured with RADIUS.
For more information about , see Switch Access with , page 145 . For more information about
RADIUS, see Configuring Radius Server Communication, page 172 .
LRE Profiles
A configuration conflict occurs if a switch cluster has Long-Reach Ethernet (LRE) switches that use both private and
public profiles. If one LRE switch in a cluster is assigned a public profile, all LRE switches in that cluster must have that
same public profile. Before you add an LRE switch to a cluster, make sure that you assign it the same public profile used
by other LRE switches in the cluster.
A cluster can have a mix of LRE switches that use different private profiles.