In an environment where it is very difficult to get downtime for maintenance/software upgrades.
Today on 6500 Sup2 performing an OS upgrade means a switch reset. Realise we would need to move to new platform/supervisor to get full benefits of ISSU.
Eager to understand from members here how successful ISSU is on either the 45xx or 65xx platform and does it really mean zero impact?
From how I read it with the 45xx, as long as the images are compatible (which may not be that often), you can load new IOS on standby supervisor and perform a sub-second failover. Only impact is <150ms while secondary sup is taking over.
With a 6500 running modular IOS it seems that one can do software updates on different modules without the need for any downtime. Not sure if this applies across all modules and whether one truly can perform software updates with zero downtime. Also, not sure if you necessarily need to have dual supervisors for this to work.
Any practical experience from those in the know would be appreciated. Typically we would only do upgrades between major releases so what is best non-impacting s/w upgrade solution that members have come across.