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Bronze

redundant switch supervisors

Hi every body!

I was reading about redundancy in switch supervisors.

There are different modes:

1) route processor redundancy(RPR)

2)Route processor redundancy(RPR+)

3)stateful switchover (SSO)

q1)I understand how these modes but my question is why one want to use any other mode but sso as fail over time is less than a second compared to other modes ?

q2) Should both supervisors be same?

Thanks a lot!

4 REPLIES
Hall of Fame Super Silver

Re: redundant switch supervisors

Hello Sarah,

q1) SSO requires identical supervisors, identical ios image and newer IOS image (it has more tight requirements) so there can be cases where RPR or RPR+ can be used but SSO cannot

q2) for SSO they need to be exactly the same model, RPR and RPR+ have lesser requirements

see

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/46sg/configuration/guide/RPR.html#wp1116237

Hope to help

Giuseppe

Bronze

Re: redundant switch supervisors

thanks a lot Giuseppe!

My book says

For RPR+ ios must be of same release. How about sup? they should be same as well?

Cisco Employee

Re: redundant switch supervisors

The sups' have to be the same as well.

regards,

-amit singh

New Member

Re: redundant switch supervisors

Hi ,

There are several modes , but every mode has its own unique circumstances. The fastest mode is not always the best mode

1)SSO enables subsecond convergence , but some state tables like HSRP encounters problems during the switchover. For example if your supervisors or RPs switch faster than your HSRP timeout , you will definetely experience a switchover in the HSRP state as well.

2) The Supervisors / RPs must be the same.

HTH

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