What is a requirement for Cisco ACI IPN to manage multidestination traffic?

Pervasive gateway is a concept related to a subnet being available on all leaf switches within an ACI fabric, not directly a requirement for multidestination traffic management across an IPN.

Unicast routing is essential for point-to-point communication but does not address the specific requirements for multidestination traffic, which involves sending data to multiple destinations.

Anycast gateway is a mechanism for gateway redundancy and localized traffic forwarding, typically for unicast traffic, not for managing multidestination traffic across an IPN.

Multicast routing is a fundamental requirement for an IPN (IP Network) to effectively manage and forward multidestination traffic within and between Cisco ACI fabrics. It enables the efficient delivery of traffic to multiple recipients simultaneously without flooding, which is crucial for services like PIM or IGMP snooping between sites.