RFC8950: Announce IPv4 with an IPv6 next-hop
Summary
RFC8950 enables announcing IPv4 routes over IPv6 sessions by using an IPv6 next-hop, allowing IPv4 to ride atop an IPv6 backbone without tunneling. The post outlines practical use cases for IPv6-only cores with IPv4 reachability, outlines how MP-BGP handles mixed IPv4/IPv6 routing, and notes broad hardware support. A lab demonstration with Container Lab and FRR illustrates a multi-router topology where IPv4 connectivity is achieved over IPv6 infrastructure.