Hsrp And Standby Command Switches - Cisco 2950 - Catalyst Switch Configuration Manual

Chapter 7 Clustering Switches
Figure 7-7
New (out-of-box)
candidate switch

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
can be assigned per cluster. Follow these guidelines when configuring a cluster standby group:
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•
•
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The cluster standby group is an HSRP group. Disabling HSRP disables the cluster standby group.
Note
The switches in the cluster standby group are ranked according to HSRP priorities. The switch with the
highest priority in the group is the active command switch (AC). The switch with the next highest priority
is the standby command switch (SC). The other switches in the cluster standby group are the passive
command switches (PC). If the active command switch and the standby command switch become
disabled at the same time, the passive command switch with the highest priority becomes the active
command switch. For the limitations to automatic discovery, see the
Configuration" section on page
78-11380-10
Discovery of Newly Installed Switches in Different Management VLANs
Command switch
VLAN 9
Switch A
AP
VLAN 9
"Standby Command Switch Characteristics" section on page
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 Catalyst 2940 switch, all standby command switches must be
Catalyst 2940 switches.
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.
VLAN 16
Switch B
AP
VLAN 16
New (out-of-box)
candidate switch
7-14. For information about changing HSRP priority values, refer to the
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
Planning a Switch Cluster
7-3. Only one cluster standby group
"Automatic Recovery of Cluster
7-11