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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter7 Clustering Switches
Planning a Switch Cluster
Discovery through the Same Management VLAN
A Catalyst 2900XL com ma nd sw itch , a Ca talyst 3500 XL command switch, or a non-LRE
Catalyst 2950 command switch running a release earlier than Cisco IOS Release 12. 1(9)E A1 must
connect to all cluster members through its management VLAN. T he d efau lt ma na geme nt VLA N i s
VLAN 1. For more information about management VLANs, see the “Management VLAN” section on
page 7-16.
Note You can avoid this limitation by using, whenever possible, a command switch that is a Catalyst3550
switch, a Catalyst 2955 switch, a Catalyst 2950 LRE switch, a non-LRE Catalyst 2950 command switch
running Cisco IOS Release 12.1(9)EA1 or later, or a Catalyst 2940 switch. These command switch es can
manage cluster members even if they belong to different management VLANs. See the “Discovery
through Different Management VLANs” section on page 7-9.
The cluster in Figure 7-4 has a command switch that is a Catalyst 2900 XL switch, a Catalyst 3500 XL
switch, or a non-LRE Catalyst2950 switch running a release earlier than Cisco IOS Release 12.1(9)EA1
with ports assigned to management VLAN 9. It discovers all but these switches:
Switches 7 and 10 because their management VLAN (VLAN4) is different from the
command-switch management VLAN (VLAN9)
Switch 9 because automatic discovery does not extend beyond a noncandidate device, which is
switch 7
Figure7-4 Discovery through the Same Management VLAN
VLAN 9
VLAN trunk 4, 9
VLAN 9
VLAN 9
VLAN 9
VLAN 9 VLAN 9
Standby command switchCommand switch
VLAN 9
Switch 7
(management
VLAN 4)
Switch 9
(management
VLAN 9)
VLAN 4
111415
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)