Route Processor Redundancy (RPR)


Prerequisites for RPR

Restrictions for RPR

Information About RPR

Default Settings for RPR

How to Configure RPR


NoteFor complete syntax and usage information for the commands used in this chapter, see these publications:

http://www.cisco.com/en/US/products/ps11846/prod_command_reference_list.html

Cisco IOS Release 15.1SY supports only Ethernet interfaces. Cisco IOS Release 15.1SY does not support any WAN features or commands.

In route processor redundancy (RPR) redundancy mode, the ports on a supervisor engine in standby mode are disabled.

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

General RPR Restrictions

Hardware Restrictions for RPR

General RPR Restrictions

When a redundant supervisor engine is in standby mode, the two Gigabit Ethernet interfaces on the standby supervisor engine are always active.

Supervisor engine redundancy does not provide supervisor engine mirroring or supervisor engine load balancing. Only one supervisor engine is active.

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.

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.

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
 
   

If configuration changes occur at the same time as a supervisor engine switchover, these configuration changes are lost.

Hardware Restrictions for RPR

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.

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.

Make separate console connections to each supervisor engine. Do not connect a Y cable to the console ports.

Except during an FSU, both supervisor engines must have the same system image (see the "Copying Files to the RP" section).

The configuration register must be set to 0x2102 (config-register 0x2102).


Note There is no support for booting from the network.


Information About RPR

Supervisor Engine Redundancy Overview

RPR Operation

Supervisor Engine Configuration Synchronization

Supervisor Engine Redundancy Overview

Catalyst 6500 series switches support 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:

A hardware failure on the active supervisor engine

Clock synchronization failure between supervisor engines

A manual switchover

RPR Operation

RPR supports the following features:

Auto-startup and bootvar synchronization between active and standby supervisor engines

Hardware signals that detect and decide the active or standby status of supervisor engines

Clock synchronization every 60 seconds from the active to the standby supervisor engine

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

An operational supervisor engine present in place of the failed unit becomes the standby supervisor engine

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:

All switching modules power up again

Remaining subsystems on the RP (including Layer 2 and Layer 3 protocols) are brought up

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

Configuring RPR Mode

Synchronizing the Supervisor Engine Configurations

Displaying the Redundancy States

Copying Files to the RP

Configuring RPR Mode

To configure RPR mode, perform this task:

 
Command
Purpose

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> enable 
Router# configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# redundancy 
Router(config-red)# mode rpr 
Router(config-red)# end 
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:

Command
Purpose

Router# show redundancy states

Displays the redundancy states.


This example shows how to display the redundancy states:

Router# show redundancy states 
my state = 13 -ACTIVE
     peer state = 8  -STANDBY HOT
           Mode = Duplex
           Unit = Primary
        Unit ID = 1
 
   
Redundancy Mode (Operational) = Route Processor Redundancy 
Redundancy Mode (Configured)  = Route Processor Redundancy 
     Split Mode = Disabled
   Manual Swact = Enabled
 Communications = Up
 
   
   client count = 11
 client_notification_TMR = 30000 milliseconds
          keep_alive TMR = 9000 milliseconds
        keep_alive count = 0
    keep_alive threshold = 18
           RF debug mask = 0x0
 
   

In this example, the system cannot enter the redundancy state because the second supervisor engine is disabled or missing:

Router# show redundancy states 
       my state = 13 -ACTIVE
     peer state = 1  -DISABLED
           Mode = Simplex
           Unit = Primary
        Unit ID = 1
 
   
Redundancy Mode (Operational) = rpr 
Redundancy Mode (Configured)  = rpr 
Redundancy State              = Non Redundant
     Maintenance Mode = Disabled
 Communications = Down      Reason: Simplex mode
 
   
   client count = 11
 client_notification_TMR = 30000 milliseconds
          keep_alive TMR = 4000 milliseconds
        keep_alive count = 0
    keep_alive threshold = 7
           RF debug mask = 0x0

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