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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 6 Clustering Swit ches Planning a Switch Cluster

Discovery through Different Management VLANs

We reco mmend using a Catal yst 3550 comma nd switch or a Catalyst 2950 co mman d switch runn ing
Release 12.1(9)EA1 or later. These command switches can discover and manage member switches in
different VLANs and different management VLANs. Catalyst 3550 member switches and Catalyst 2950
member switches running Release 12.1(9)EA1 or later must be connected through at least one VLAN in
common with the command switch. All other member switches must be connected to the command
switch thro ugh thei r manage ment VLAN.
In cont rast, a Catal yst 2900 X L co mma nd sw it ch, a Catal yst 2950 c om mand sw itch ru nning a r ele ase
earlier than 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 information
about discovery through the same management VLAN on these switches, see the Discovery through the
Same Management VLAN section on page 6-8.
The Catal yst 2950 comma nd switch (r unning Re lease 12.1( 9)EA1 or l ater) in Figure 6-5 a nd t he
Catalyst 3550 c ommand sw itch in Figure 6-6 have ports a ssigned to VL ANs 9, 16, an d 6 2. The
management VLAN on the Catalyst 2950 command switch is VLAN 9. Each command switch discovers
the switches in the different management VLANs except these:
Switches 7 a nd 10 (s witc hes i n ma na geme nt VLA N 4) bec au se they are n ot c onne cte d throu gh a
comm on V LAN ( mean ing VL AN s 62 an d 9) w it h th e co mm and sw it ch
Switch 9 beca use autom atic discovery does not extend beyond a nonca ndidat e device, which is
switch 7
Figure 6-5 Discovery through Different Management VLANs with a Layer 2 Command Switch
Catalyst 1900,
Catalyst 2820,
Catalyst 2900 XL,
Catalyst 2950, and
Catalyst 3500 XL
switches
VLAN 62
VLAN trunk 4, 62
VLAN 62
VLAN 16
(management
VLAN 9)
VLAN 16 VLAN 9
Catalyst 2950
standby command switch
Catalyst 2950
command switch
VLAN 9
Switch 7
(management
VLAN 4)
Switch 9
(management
VLAN 62)
VLAN 4
74049
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)