Router Processor Redundancy (RPR)

Redundant Supervisor Engines – Handy having two brains!

When implemented back in the day in IOS 12.1(13)F it was a great technology. Over time NSR and SSO have addressed the shortcomings with better failover times. RPR on the 6500 series is around 2-4 minutes and on the 4500 series less than 60 seconds. RPR+ only available on the 6500 series comes in at around 30-60 seconds. In this day and age that is a noticeable downtime and isn’t transparent to the end user.

Supervisor engine that forwards all the L2/L3 traffic is the active supervisor engine. The other supervisor engine waits in standby. Both supervisor engines talk to each other.

Trigger	Event
Routing/Switching processor crash	Switching modules power cycled
Manual	Subsystems on standby are activated
Removal	ACLs reprogrammed into Supervisor engine.

RPR+

Improved switch over times and Reduced to around 30-60 seconds with no reloading of modules required.

Easy configuration makes RPR (when it was used) too good to not configure!

sw(config)# redundancy
sw(config-red)# mode rpr-plus

Simple as that.

Verify with the following

sw# show redundancy states