Cisco Catalyst 3550 Series User Manual

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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 6 Clustering Switches
Planning a Switch Cluster
Figure 6-8 Discovery of Newly Installed Switches
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 6-3. Only one cluster standby group
can be assigned per cluster. Follow these guidelines when configuring a cluster standby group:
• 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, all standby command switches must be
Catalyst 2955 switches.
• When the command switch is a Catalyst 2950 LRE switch, all standby command switches must be
Catalyst 2950 LRE switches.
• When the command switch is a non-LRE Catalyst 2950 switch running Cisco IOS
Release 12.1(9)EA1 or later, all standby command switches must be non-LRE Catalyst 2950
switches running Cisco IOS Release 12.1(9)EA1 or later.
• When the command switch is a non-LRE Catalyst 2950 switch running Cisco IOS
Release 12.1(6)EA2 or later, all standby command switches must be non-LRE Catalyst 2950
switches running Cisco IOS Release 12.1(6)EA2 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, non-LRE Catalyst 2950, and
Catalyst 3500 XL switches.
Note The cluster standby group is an HSRP group. Disabling HSRP disables the cluster standby group.
Si
Si
Command switch
New (out-of-box)
Catalyst 2950
switch
AP
Catalyst 2950
switch
VLAN 9
VLAN 9
VLAN 16
VLAN 16
New (out-of-box)
Catalyst 3550
switch
Catalyst 3500 XL
switch
65278
AP
(Management
VLAN 9)
(Management
VLAN 16)

Cisco Catalyst 3550 Series Specifications

General

Brand	Cisco
Model	Catalyst 3550 Series
Category	Network Router
Language	English