Understanding VLANs
Determining the Management VLAN for a New Switch
If you add a new switch to an existing cluster and the cluster is using a management VLAN other than
the default VLAN 1, the command switch automatically senses that the new switch has a different
management VLAN and has not been configured. The command switch issues commands to change the
management VLAN on the new switch to match the one used by the cluster. This automatic change
occurs for new, out-of-box switches that do not have a config.text file and for which there have been no
changes to the running configuration.
Before a new switch can be added to a cluster, it must be connected to a port that belongs to the cluster
management VLAN. If the cluster is configured with a management VLAN other than the default, the
command switch changes the management VLAN for new switches when they are connected to the
cluster. In this way, the new switch can exchange Cisco Discovery Protocol (CDP) messages with the
command switch and be proposed as a cluster candidate.
For the command switch to change the management VLAN on a new switch, there must have been no
Note
changes to the new switch configuration, and there must be no config.text file.
Because the switch is new and unconfigured, its management VLAN is changed to the cluster
management VLAN when it is first added to the cluster. All ports that have an active link at the time of
this change become members of the new management VLAN.
For information about the role management VLANs play in switch clusters, see the
VLAN" section on page
Changing the Management VLAN for a Cluster
Beginning in privileged EXEC mode on the command switch, follow these steps to configure the
management VLAN interface through a Telnet or Secure Shell (SSH) connection:
Command
Step 1
configure terminal
Step 2
cluster management-vlan vlanid
Step 3
show running-config
Catalyst 2950 Desktop Switch Software Configuration Guide
13-4
6-20.
Purpose
Enter global configuration mode.
Change the management VLAN for the cluster. This ends your Telnet
session. Change the port through which you are connected to the switch
to a port in the new management VLAN.
Verify the change.
Chapter 13
Configuring VLANs
"Management
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