Operational Considerations for Multicast over RIFT-based Data Center Fabrics

RIFT (Routing in Fat Trees) is increasingly used as an underlay routing protocol in modern data center fabrics. However, RIFT does not natively define mechanisms for multicast traffic distribution. This document provides operational guidance and best practices for deploying multicast in RIFT-based data center fabrics. It analyzes PIM, EVPN multicast, BIER, and head-end replication, highlighting trade-offs in scalability, efficiency, and operational complexity. This document does not define new protocol mechanisms. It aims to assist network operators in making informed design decisions when deploying multicast services over RIFT-based fabrics.