You can use Internet Group Management Protocol (IGMP) to add receivers to the IP Multicast group membership within the Layer 2 domains.
IGMP allows receivers to send requests to the multicast groups they want to join. Becoming a member of a multicast group allows routers to forward traffic for the multicast groups on the Layer 3 segment where the receiver is connected to switch port.
You can use IGMP snooping to limit the physical switch ports participating in the multicast group to only vSAN VMkernel port uplinks. IGMP snooping is configured with an IGMP snooping querier. The need to configure an IGMP snooping querier to support IGMP snooping varies by switch vendor. Consult your specific switch vendor for IGMP snooping configuration.
vSAN supports both IGMP version 2 and IGMP version 3. When you perform the vSAN deployment across Layer 3 network segments, you can configure a Layer 3 capable device such as a router or a switch with a connection and access to the same Layer 3 network segments.
All VMkernel ports on the vSAN network subscribe to a multicast group using IGMP to avoid multicast flooding all network ports.