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Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 5 Clustering Switches
Planning a Switch Cluster
Discovery of Newly Installed Switches
A new, out-of-the-box switch is set with the default VLAN, VLAN 1. By default, all access ports on the
new switch are assigned to VLAN 1.
To add a new switch to a cluster, it must be connected to the cluster through an access port. When the
new switch joins a cluster, its default VLAN changes to the VLAN of the immediately upstream
neighbor. The new switch also configures its access port to belong to the VLAN of the immediately
upstream neighbor.
An access port (AP) carries the traffic of and belongs to only one VLAN. For more information about
access ports, see the
“Access Ports” section on page 8-2
.
For example, the command switch in
Figure 5-7
belongs to VLAN 9 and VLAN 16.
•
A new Catalyst 3550 switch automatically configures the access port to belong to the immediately
upstream VLAN, VLAN 9.
•
A new Catalyst 2950 switch configures the access port to belong to the upstream VLAN, VLAN 16.
The management VLAN of the Catalyst 2950 switch becomes VLAN 16.
Figure 5-7
Discovery of Newly Installed Switches
Si
Si
Catalyst 3550
command switch
New (out-of-box)
Catalyst 2950
switch
AP
Catalyst 2950
switch
VLAN 9
VLAN 9
VLAN 16
VLAN 16
New (out-of-box)
Catalyst 3550
switch
Catalyst 3500 XL
switch
65278
AP
(Management
VLAN 9)
(Management
VLAN 16)