Describes the process of upgrading or downgrading huge fabrics with large numbers of switches across multiple maintenance groups.
A huge fabric upgrade or downgrade is a maintenance operation that
involves large numbers of switches split into different maintenance groups
occurs over a series of days with staggered timing
allows at most two different APIC and switch software releases in the fabric simultaneously, and
provides limited supported operations during mixed-release periods.
Mixed release considerations
During huge fabric upgrades or downgrades, you can have at most two different APIC and switch software releases in the fabric at any given time. However, supported operations in those situations are limited. See Operations allowed during mixed versions on Cisco ACI switches for more information.