High Availability - Cisco WS-C6506 Software Manual

Configuring Redundant Supervisor Engines on the Switch
This example shows the console output on the standby supervisor engine when you force a switchover
from the active to the standby supervisor engine:
Cisco Systems Console
Enter password:
12/07/1998,17:04:43:MLS-5:Multilayer switching is enabled
12/07/1998,17:04:43:MLS-5:Netflow Data Export disabled
12/07/1998,17:04:44:SYS-5:Module 2 is online
12/07/1998,17:04:45:SYS-5:Module 5 is online
12/07/1998,17:04:45:SYS-5:Module 7 is online
12/07/1998,17:04:45:SYS-5:Module 3 is online
12/07/1998,17:04:52:MLS-5:Route Processor 172.20.52.6 added
12/07/1998,17:05:10:SYS-5:Module 8 is online
12/07/1998,17:05:14:SYS-5:Module 9 is online
12/07/1998,17:05:22:SYS-5:Module 4 is online
12/07/1998,17:06:13:SYS-5:Module 1 is in standby mode
Supervisor image synchronization process will start in 10 seconds
12/07/1998,17:06:37:SYS-5:Ports on standby supervisor(Module 1) are UP
12/07/1998,17:06:41:SYS-5:Active supervisor is synchronizing the NMP image.
12/07/1998,17:06:44:SYS-5:The active supervisor has synchronized the NMP image.
Console>

High Availability

High availability allows you to minimize the switchover time from the active supervisor engine to the
standby supervisor engine if the active supervisor engine fails.
Prior to this feature, fast switchover ensured that a switchover to the standby supervisor engine happened
quickly. However, with fast switchover, because the state of the switch features before the switchover
was unknown, you had to reinitialize and restart all the switch features when the standby supervisor
engine assumed the active role.
High availability removes this limitation; high availability allows the active supervisor engine to
communicate with the standby supervisor engine, keeping feature protocol states synchronized.
Synchronization between the supervisor engines allows the standby supervisor engine to take over in the
event of a failure.
In addition, high availability provides a versioning option that allows you to run the different software
images on the active and standby supervisor engines.
These features are discussed in these sections:
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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
23-8
High-Availability Overview, page 23-9
High-Availability Supported Features, page 23-10
High-Availability Configuration Guidelines, page 23-11
Versioning Overview, page 23-11
CLI Commands, page 23-12
Loading a Different but Compatible Image on the Standby Supervisor Engine, page 23-14
Chapter 23 Configuring Redundancy
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