Route Processor Redundancy (RPR)
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Prerequisites for RPR
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Restrictions for RPR
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Information About RPR
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Default Settings for RPR
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How to Configure RPR
Note
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For complete syntax and usage information for the commands used in this chapter, see these publications:
http://www.cisco.com/en/US/products/ps11845/prod_command_reference_list.html
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Cisco IOS Release 15.0SY supports only Ethernet interfaces. Cisco IOS Release 15.0SY does not support any WAN features or commands.
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In route processor redundancy (RPR) redundancy mode, the ports on a supervisor engine in standby mode are disabled.
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RPR supports IPv6 multicast traffic.
Tip
For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:
http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html
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Prerequisites for RPR
None.
Restrictions for RPR
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General RPR Restrictions
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Hardware Restrictions for RPR
General RPR Restrictions
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When a redundant supervisor engine is in standby mode, the two Gigabit Ethernet interfaces on the standby supervisor engine are always active.
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Supervisor engine redundancy does not provide supervisor engine mirroring or supervisor engine load balancing. Only one supervisor engine is active.
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Configuration changes made through SNMP are not synchronized to the standby supervisor engine. After you configure the switch 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 standby supervisor engine.
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Supervisor engine switchover takes place after the failed supervisor engine completes a core dump. A core dump can take up to 15 minutes. To get faster switchover time, disable core dump on the supervisor engines.
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You cannot perform configuration changes during the startup (bulk) synchronization. If you attempt to make configuration changes during this process, the following message is generated:
Config mode locked out till standby initializes
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If configuration changes occur at the same time as a supervisor engine switchover, these configuration changes are lost.
Hardware Restrictions for RPR
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Cisco IOS supports redundant configurations where the supervisor engines are identical. If they are not identical, one will boot first and become active and hold the other supervisor engine in a reset condition.
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Each supervisor engine must have the resources to run the switch on its own, which means all supervisor engine resources are duplicated, including all flash devices.
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Make separate console connections to each supervisor engine. Do not connect a Y cable to the console ports.
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Except during an FSU, both supervisor engines must have the same system image (see the "Copying Files to the RP" section).
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The configuration register must be set to 0x2102 (config-register 0x2102).
Note
There is no support for booting from the network.
Information About RPR
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Supervisor Engine Redundancy Overview
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RPR Operation
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Supervisor Engine Configuration Synchronization
Supervisor Engine Redundancy Overview
The switch supports fault resistance by allowing a standby supervisor engine to take over if the primary supervisor engine fails. RPR supports a switchover time of 2 or more minutes.
The following events cause a switchover:
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A hardware failure on the active supervisor engine
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Clock synchronization failure between supervisor engines
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A manual switchover
RPR Operation
RPR supports the following features:
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Auto-startup and bootvar synchronization between active and standby supervisor engines
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Hardware signals that detect and decide the active or standby status of supervisor engines
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Clock synchronization every 60 seconds from the active to the standby supervisor engine
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A standby supervisor engine that is booted but not all subsystems are up: if the active supervisor engine fails, the standby supervisor engine become fully operational
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An operational supervisor engine present in place of the failed unit becomes the standby supervisor engine
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Support for fast software upgrade (FSU) (see Chapter 6 "Fast Software Upgrade".)
When the switch is powered on, RPR runs between the two supervisor engines. The supervisor engine that boots first becomes the RPR active supervisor engine. The route processor (RP) and Policy Feature Card (PFC) become fully operational. The RP and PFC on the standby supervisor engine come out of reset but are not operational.
In a switchover, the standby supervisor engine become fully operational and the following occurs:
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All switching modules power up again
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Remaining subsystems on the RP (including Layer 2 and Layer 3 protocols) are brought up
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Access control lists (ACLs) are reprogrammed into supervisor engine hardware
Note
In a switchover, there is a disruption of traffic because some address states are lost and then restored after they are dynamically redetermined.
Supervisor Engine Configuration Synchronization
Note
Configuration changes made through SNMP are not synchronized to the standby supervisor engine. After you configure the switch 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 standby supervisor engine.
During RPR mode operation, the startup-config files and the config-register configurations are synchronized by default between the two supervisor engines. In a switchover, the new active supervisor engine uses the current configuration.
Default Settings for RPR
None.
How to Configure RPR
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Configuring RPR Mode
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Synchronizing the Supervisor Engine Configurations
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Displaying the Redundancy States
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Copying Files to the RP
Configuring RPR Mode
To configure RPR mode, perform this task:
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Step 1 |
Router(config)# redundancy |
Enters redundancy configuration mode. |
Step 2 |
Router(config-red)# mode rpr |
Configures RPR. When this command is entered, the standby supervisor engine is reloaded and begins to work in RPR mode. |
This example shows how to configure the system for RPR:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# redundancy
Router(config-red)# mode rpr
Router# show running-config
Router# show redundancy states
Synchronizing the Supervisor Engine Configurations
During normal operation, the startup-config and config-registers configuration are synchronized by default between the two supervisor engines. In a switchover, the new active supervisor engine uses the current configuration.
Note
Do not change the default auto-sync configuration.
Displaying the Redundancy States
To display the redundancy states, perform this task:
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Router# show redundancy states |
Displays the redundancy states. |
This example shows how to display the redundancy states:
Router# show redundancy states
peer state = 8 -STANDBY HOT
Redundancy Mode (Operational) = Route Processor Redundancy
Redundancy Mode (Configured) = Route Processor Redundancy
client_notification_TMR = 30000 milliseconds
keep_alive TMR = 9000 milliseconds
keep_alive threshold = 18
In this example, the system cannot enter the redundancy state because the second supervisor engine is disabled or missing:
Router# show redundancy states
Redundancy Mode (Operational) = rpr
Redundancy Mode (Configured) = rpr
Redundancy State = Non Redundant
Maintenance Mode = Disabled
Communications = Down Reason: Simplex mode
client_notification_TMR = 30000 milliseconds
keep_alive TMR = 4000 milliseconds
Copying Files to the RP
Use the following command to copy a file to the bootflash: device on an active RP:
Router# copy source_device:source_filename bootflash:target_filename
Use the following command to copy a file to the bootflash: device on a standby RP:
Router# copy source_device:source_filename slavebootflash:target_filename
Tip
For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:
http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html
Participate in the Technical Documentation Ideas forum