Overview of IGMP Snooping Over VXLAN
By default, multicast traffic over VXLAN is flooded in the VNI/VLAN like any broadcast and unknown unicast traffic. With IGMP snooping enabled, each VTEP can snoop IGMP reports and only forward multicast traffic towards interested receivers.
The configuration of IGMP snooping is the same in VXLAN as in the configuration of IGMP snooping in a regular VLAN domain. For more information on IGMP snooping, see the Configuring IGMP Snooping section in the Cisco Nexus 9000 Series NX-OS Multicast Routing Configuration Guide, Release 7.x.