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Catalyst 2940 Switch Software Configuration Guide
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Chapter 5 Clustering Switches
Planning a Switch Cluster
Figure 5-5 Discovery of Newly Installed Switches in Different Management VLANs
HSRP and Standby Command Switches
The switch supports Hot Standby Router Protocol (HSRP) so that you can configure a group of standby
command switches. Because a command switch manages the forwarding of all communication and
configuration information to all the member switches, we strongly recommend that you configure a
cluster standby command switch to take over if the primary command switch fails.
A cluster standby group is a group of command-capable switches that meet the requirements described
in the “Standby Command Switch Characteristics” section on page 5-2. Only one cluster standby group
can be assigned per cluster.
Note • When the command switch is a Catalyst 3550 switch, all standby command switches must be
Catalyst 3550 switches.
• When the command switch is a Catalyst 2955 switch running Cisco IOS Release 12.1(12c)EA1 or
later, all standby command switches must be Catalyst 2955 switch running Cisco IOS
Release 12.1(12c)EA1 or later.
• When the command switch is a Catalyst 2950 switch running Cisco IOS Release 12.1(9)EA1 or
later, all standby command switches must be Catalyst 2950 switches running Cisco IOS
Release 12.1(9)EA1 or later.
• When the command switch is a Catalyst 2950 switch running Cisco IOS Release 12.1(6)EA2 or
later, all standby command switches must be Catalyst 2950 switches running Cisco IOS
Release 12.1(6)EA2 or later.
• When the command switch is a Catalyst 2940 switch running Cisco IOS Release 12.1(13)AY or
later, all standby command switches must be Catalyst 2940 switches running Cisco IOS
Release 12.1(13)AY or later.
• When the command switch is running Cisco IOS Release 12.0(5)WC2 or earlier, the standby
command switches can be these switches: Catalyst 2900 XL, Catalyst 2950, and Catalyst 3500 XL
switches.
Command switch
New (out-of-box)
Catalyst 1900
switch
AP
Catalyst 2940
switch
VLAN 9
VLAN 9
VLAN 16
VLAN 16
New (out-of-box)
Catalyst 2820
switch
Catalyst 3500 XL
switch
AP
(Management
VLAN 9)
(Management
VLAN 16)
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