Protocol Independent Multicast sparse mode (PIM-SM) is designed for efficient routing to multiple receivers in a multicast group across an inter-pod network (IPN). PIM sparse mode is best suited for environments where receivers are dispersed because it allows for explicit join messages to control the flow of traffic. This makes it ideal for scenarios where broadcast, unknown unicast, and multicast flooding between Cisco ACI pods is required. References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )