Understanding Supervisor Engine Redundancy
RPR Operation
RPR supports the following features:
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The two Gigabit Ethernet interfaces on the redundant supervisor engine are always active.
Note
When the switch is powered on, RPR runs between the two supervisor engines. The supervisor engine
that boots first, either in slot 1 or 2, becomes the RPR active supervisor engine. The Multilayer Switch
Feature Card (MSFC or MSFC2) and Policy Feature Card (PFC or PFC2) become fully operational. The
MSFC and PFC on the redundant supervisor engine come out of reset but are not operational.
The following events cause an RPR switchover:
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In a switchover, the redundant supervisor engine becomes fully operational and the following occurs:
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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
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, either in slot 1 or 2, becomes the active supervisor engine. The Multilayer Switch Feature
Card (MSFC or MSFC2) and Policy Feature Card (PFC or PFC2) become fully operational. The MSFC
and PFC on the redundant supervisor engine come out of reset but are not operational.
Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E
5-2
Auto-startup and bootvar synchronization between active and redundant supervisor engines
Hardware signals that detect and decide the active or redundant status of supervisor engines
Clock synchronization every 60 seconds from the active to the redundant supervisor engine
A redundant supervisor engine that is booted but not all subsystems are up: if the active supervisor
engine fails, the redundant supervisor engine become fully operational
An operational supervisor engine present in place of the failed unit becomes the redundant
supervisor engine
Support for fast software upgrade (FSU) (See the
page
5-9).
Clock synchronization failure between supervisor engines
MSFC or PFC failure on the active supervisor engine
A manual switchover.
All switching modules power up again
Remaining subsystems on the MSFC (including Layer 2 and Layer 3 protocols) are brought up
Access control lists (ACLs) are reprogrammed into supervisor engine hardware
Chapter 5
Configuring RPR and RPR+ Supervisor Engine Redundancy
"Performing a Fast Software Upgrade" section on
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