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Software Configuration Guide—Release 12.2(25)EWA
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Chapter9 Configuring Switches wi th Web-Based Tools
Configuring and Using the Network Assistant
Clustering Overview
A switch cluster is a set of up to 16connected, cluster-capable Catalyst switches that are managed as a
single entity. The switches in the cluster use the switch clustering technology so that you can configure
and troubleshoot a group of different Catalyst 4500 series switch platforms thro ugh a single IP address.
Using switch clusters simplifies the management of multiple switches, regardless of their physical
location and platform families.
Note By default, Network Assistant in clustering mode discovers up to 7 hops away.
In a switch cluster, one switch must be the cluster commander switch, and up to 15other switches can
be cluster member switches. The total number of switches in a cluster cannot exceed 16switches. The
cluster command switch is the single point of access used to configure, manage, and monitor the cluster
member switches. Cluster members can belong to only one cluster at a time.
Note Always chose a Catalyst 4500 or 4948 series switch as the cluster command switch.
Cluster Command Switch Characteristics
A cluster command switch must meet these requirements:
•It is using Cisco IOS Release 12.2(20)EWA or later.
•It has an IP address.
•It has Cisco Discovery Protocol (CDP) version 2 enabled (the default).
•It is using cluster-capable software and has clustering enabled.
•It has IP HTTP (or HTTPS) server enabled.
Note On a Catalyst 4500 series switch, neither HTTP or HTTPS is enabled by default.
•It has 16 VTY lines.
Note On a Catalyst 4500 series switch, the default is 4 lines. You configure the switch to set the value
to 16.
•It is not a command or cluster member switch of another cluster.
Note If your switch cluster contains a Catalyst 4500 series switch, the cluster command switch must also be
a Catalyst 4500 series switch.
Network Assistant and VTY
Network Assistant uses virtual terminal (VTY) lines to communicate with the cluster command device.
Catalyst 4500 series switches have 5 VTY lines configured by default. Network Assistant can employ
an additional 8 lines. Therefore, you should configure the maximum number of lines (or at least, 8 + 5
= 13) so that Network Assistant can communicate with the switch and not u se VTY lines that might be
needed for telnet.