Cisco SD-WAN overlay multicast routing supports the Internet Group Management Protocol (IGMP) version 2 (defined in RFC 2236). Cisco vEdge devices use IGMP to process receiver membership reports for the hosts in a particular VPN and to determine, for a given group, whether multicast traffic should be forwarded and state should be maintained. vEdge routers listen for both IGMPv1 and IGMPv2 group membership reports.