redundancy sso mode

[sarahr202]

Hi everybody

If a switch is configured for SSO mode, then stand-by supervisor engine stops at " FIB table synchronization"  and waits for  active supervisor to fail.

If active supervisor fails, then standby sup will perform following in sequence: Layer3 protocol initialized, routing tables converged, FIB table updated.

What exactly standby sup does when  it performs FIB table synchronization ?

thanks and have a great weekend.

[Reza Sharifi · Accepted solution]

Hi Sarah,

Have a look at thes doc for detail explanation of sequence of events:

During normal NSF operation, CEF on the active  supervisor engine synchronizes its current FIB and adjacency databases  with the FIB and adjacency databases on the standby supervisor engine.  Upon switchover, the standby supervisor engine initially has FIB and  adjacency databases that are mirror images of those that were current on  the active supervisor engine. CEF keeps the forwarding engine on the  standby supervisor engine current with changes that are sent to it by  CEF on the active supervisor engine. The forwarding engine can continue  forwarding after a switchover as soon as the interfaces and a data path  are available.

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/01xo/configuration/guide/NSFwSSO.html

HTH

[sarahr202]

thanks Reza

Thanks for the link

Just another question arose in my mind.

Does RPR, RPR+ , SSO modes require both supervisors in a chasis have to similar i.e if one is sup 720 the other must be 720 as well ?

thanks and have a great weekend

[Reza Sharifi · Accepted solution]

Hi Sarah,

That is correct.  The hardware and software must be the same. If for example you have 2 Sup 720 in a 6500 and one sup has PFC-3 and the other Sup has PFC-3XL, they only way you can  make it work is by lowering the 3CXL to 3C using the command line. Lowest common denominator.

But generally you want to have the same exact software and hardware componenets in both sups.

Have a nice weekend

HTH