ACI underlay protocols, i.e. COOP, IS-IS and MP-BGP, spans across pods. Create QoS policies to make sure those protocols have higher priority.

A single APIC Cluster is required in a Multi-Pod design. It is important to place the APIC Controllers in different locations in order to maximize redundancy and reliability.

ACI Multi-Pod requires an IP Network supporting PIM-Bidir.

ACI Multi-Pod does not support Firewall Clusters across Pods. Firewall Clusters should always be local.

Multi-Pod requires multiple APIC Controller Clusters, one per pod. Make sure those clusters can communicate to each other through a highly available connection.