[c-nsp] SUP720 to RSP720 upgrade using SSO

[Ross Halliday]

> > Does anyone know if it's possible to upgrade two SUP720-3B modules to
> > RSP720-3C (one at a time) using SSO on a 7600, thus minimizing downtime?
> 
> Supervisors must (physically) match exactly within a chassis. You'll find
> that the primary will boot and then the secondary will not fully
> initialise
> because the hardware doesn't match the primary. Therefore, SSO is not an
> option.

Even if it were, the SUPs wouldn't come up at the proper PFC/DFC level and downgrade to match the current operating mode, so you'd still need to take a chassis-wide outage to make it an actual upgrade and not just an exercise in yanking cards.

Cheers
Ross