5-9
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 5 Clustering Switches
Planning a Switch Cluster
Discovery through Different Management VLANs
We strongly recommend that a Catalyst 3550 switch be the command switch when the cluster has
Catalyst 1900, Catalyst 2820, Catalyst 2900 XL, Catalyst 2950, and Catalyst 3500 XL member
switches. These member switches must connect to each other and to a Catalyst 3550 command switch
through their management VLAN, which is VLAN 1 by default. When these member switches are
directly connected to a Catalyst 3550 command switch, the management VLAN of these member
switches can be different.
For information about discovery through the same management VLAN on these switches, see the
“Discovery through the Same Management VLAN” section on page 5-8
. For information about
management VLANs on these switches, refer to the software configuration guide for that specific switch.
The command switch in
Figure 5-5
has ports assigned to VLANs 9, 16, and 62. It discovers all the
switches in the different management VLANs except these:
•
Switches 7 and 10 because their management VLAN (VLAN 4) is different from the
command-switch management VLAN (VLAN 9)
•
Switch 9 because automatic discovery does not extend beyond a noncandidate device, which is
switch 7
Figure 5-5
Discovery through Different Management VLANs
Si
Si
Catalyst 1900,
Catalyst 2820,
Catalyst 2900 XL,
Catalyst 2950, and
Catalyst 3500 XL
switches
VLAN 62
VLAN trunk 4, 62
VLAN 62
VLAN 16
VLAN 9
VLAN 16
VLAN 9
Catalyst 3550
standby command switch
Catalyst 3550
command switch
VLAN 9
Switch 7
(management
VLAN 4)
Switch 9
(management
VLAN 62)
VLAN 4
54983
Switch 3
(management
VLAN 16)
Switch 4
(management
VLAN 16)
Switch 10
(management
VLAN 4)
Switch 8
(management
VLAN 9)
Switch 6
(management
VLAN 9)
Switch 5
(management
VLAN 62)