EVPN Optimized Inter-Subnet Multicast (OISM) Forwarding
Juniper Networks
Juniper Networks
Juniper Networks
Juniper Networks
Nokia
Cisco Systems
Ethernet VPN (EVPN) provides a service that allows a single Local Area Network (LAN), i.e., a single IP subnet, to be distributed over multiple sites. The sites are interconnected by an IP or MPLS backbone. Intra-subnet traffic (either unicast or multicast) always appears to the endusers to be bridged, even when it is actually carried over the IP backbone. When a single "tenant" owns multiple such LANs, EVPN also allows IP unicast traffic to be routed between those LANs. This document specifies new procedures that allow inter- subnet IP multicast traffic to be routed among the LANs of a given tenant, while still making intra-subnet IP multicast traffic appear to be bridged. These procedures can provide optimal routing of the inter-subnet multicast traffic, and do not require any such traffic to leave a given router and then reenter that same router. These procedures also accommodate IP multicast traffic that needs to travel to or from systems that are outside the EVPN domain.