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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 6 Clustering Switches
Planning a Sw it ch Cl uster

Discovery through the Same Management VLAN

A Catalyst 2900 XL command switch, a Ca talyst 2950 comma nd switch ru nning a rele ase earl ier than
Release 12 .1(9) EA1, or a Catal yst 3500 XL comm and switch must connec t to all cluste r members
through its manag emen t VLAN. Th e default ma nageme nt VLAN is VLAN 1. For mo re inform ation
about ma nagement VLANs, s ee the Mana gem ent VL AN se ct ion o n page 6-18.
Note You can avoid this limita tion by using, wh enever possible, a Cata lyst 3550 co mman d switc h or a
Catalyst 2950 com ma nd swit ch ru nni ng Re le ase 1 2. 1(9 )EA1 or la ter. The se comm an d swi tc hes c an
manage cluster members even if they belong to different management VLANs. See the Discovery
through Different Manage ment V LANs sect ion on page 6-9.
The command switch in Figure 6-4 has ports assigned to management VLAN 9. It discovers all bu t these
switches:
Switches 7 and 10 because their management VLAN (VLAN 4) is different from the
command-switch management VLAN (VLAN 9)
Switch 9 beca use autom atic discovery does not extend beyond a nonca ndidat e device, which is
switch 7
Figure 6-4 Discovery through the Same Management VLAN
Catalyst 1900,
Catalyst 2820,
Catalyst 2900 XL,
Catalyst 2950, and
Catalyst 3500 XL
switches
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
65277
Catalyst 2900 XL, Catalyst 2950,
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)