The following figure shows a sample topology using Multicast.

The Edge Service Gateway uplink interface is connected to the physical infrastructure through the vSphere distributed switch. The Edge Service Gateway internal interface is connected to a logical router through a logical transit switch. The logical router's default gateway is the ESG's internal interface IP address ( The router ID is the logical router's uplink interface---in other words, the IP address that faces the ESG ( In this topology, Multicast traffic is replicated in an optimal way, across subnets, between sources and receivers inside or outside the NSX domain.

The image is described in the surrounding text.