Chapter 8
Configuring RPR and RPR+ Supervisor Engine Redundancy
In a switchover, there is a disruption of traffic because some address states are lost and then restored after
Note
they are dynamically redetermined.
RPR+ Operation
When RPR+ mode is used, the redundant supervisor engine is fully initialized and configured, which
shortens the switchover time. The active supervisor engine checks the image version of the redundant
supervisor engine when the redundant supervisor engine comes online. If the image on the redundant
supervisor engine does not match the image on the active supervisor engine, RPR redundancy mode is
used.
With RPR+, the redundant supervisor engine is fully initialized and configured, which shortens the
switchover time if the active supervisor engine fails or if a manual switchover is performed.
When the router is powered on, RPR+ runs between the two supervisor engines. The supervisor engine
that boots first becomes the active supervisor engine. The Multilayer Switch Feature Card and Policy
Feature Card become fully operational. The MSFC and PFC on the redundant supervisor engine come
out of reset but are not operational.
RPR+ enhances RPR by providing the following additional benefits:
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Supervisor Engine Configuration Synchronization
These sections describe supervisor engine configuration synchronization:
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Configuration changes made through SNMP are not synchronized to the redundant supervisor engine.
Note
After you configure the router through SNMP, copy the running-config file to the startup-config file on
the active supervisor engine to trigger synchronization of the startup-config file on the redundant
supervisor engine and with RPR+, reload the redundant supervisor engine and MSFC.
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Reduced switchover time
Depending on the configuration, the switchover time is 30 or more seconds.
Installed modules are not reloaded
Because both the startup configuration and the running configuration are continually synchronized
from the active to the redundant supervisor engine, installed modules are not reloaded during a
switchover.
Online insertion and removal (OIR) of the redundant supervisor engine
RPR+ allows OIR of the redundant supervisor engine for maintenance. When the redundant
supervisor engine is inserted, the active supervisor engine detects its presence and begins to
transition the redundant supervisor engine to fully initialized state.
Synchronization of OIR events
Manual user-initiated switchover using the redundancy force-switchover command
RPR Supervisor Engine Configuration Synchronization, page 8-4
RPR+ Supervisor Engine Configuration Synchronization, page 8-4
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
Understanding RPR and RPR+
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