An engineer must perform a Cisco ACI fabric upgrade that minimizes the impact on user...

 To perform a Cisco ACI fabric upgrade that minimizes the impact on user traffic and allows only permitted users to perform an upgrade, the following configuration steps should be taken:

Divide Cisco APIC controllers into two or more maintenance groups: This step involves organizing the APIC controllers into separate maintenance groups to allow for a phased upgrade process, reducing the impact on user traffic5.

Divide switches into two or more maintenance groups: This step involves organizing the switches into separate maintenance groups, which allows for a controlled and phased upgrade process, minimizing the impact on the network during the upgrade5.