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6-8
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 6 Clustering Switches
Planning a Switch Cluster
Discovery through the Same Management VLAN
A Catalyst 2900 XL command switch, a non-LRE Catalyst 2950 command switch running a release
earlier than Cisco IOS Release 12.1(9)EA1, or a Catalyst 3500 XL command switch must connect to all
cluster members through its management VLAN. The default management VLAN is VLAN 1. For more
information about management VLANs, refer to the software configuration guide for the specific switch.
Note
You can avoid this limitation by using, whenever possible, a Catalyst 3550 command switch, a
Catalyst 2955 switch, a Catalyst 2950 LRE switch, or a non-LRE Catalyst 2950 command switch
running Cisco IOS Release 12.1(9)EA1 or later. These command switches can manage cluster members
even if they belong to different management VLANs. See the
Management VLANs” section on page 6-9
.
has ports assigned to management VLAN 9. It discovers all but these
switches:
•
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 6-4
Discovery through the Same Management VLAN
Catalyst 1900,
Catalyst 2820,
Catalyst 2900 XL,
Catalyst 2950,
Catalyst 2955, and
Catalyst 3500 XL
switches
VLAN 9
VLAN trunk 4, 9
VLAN 9
VLAN 9
VLAN 9
VLAN 9
VLAN 9
Standby command switch
Command switch
VLAN 9
Switch 7
(management
VLAN 4)
Switch 9
(management
VLAN 9)
VLAN 4
87331
Catalyst 2900 XL,
Catalyst 2950, Catalyst 2955,
or Catalyst 3500 XL command
and standby command switches
Switch 3
(management
VLAN 9)
Switch 4
(management
VLAN 9)
Switch 10
(management
VLAN 4)
Switch 8
(management
VLAN 9)
Switch 6
(management
VLAN 9)
Switch 5
(management
VLAN 9)