Using Multicast, a source can send a single copy of data to a single multicast address, which is then distributed to a group or recipients.

NSX uses two multicast routing protocols: Internet Group Management Protocol (IGMPv2) and Protocol Independent Multicast (PIM). PIM sparse mode is supported (PIM-SM). PIM is used on ESGs, but not on the DLR.

Attention: During vMotion of virtual machines that are receivers of multicast, a 1–2 second multicast traffic loss can occur.
For more information about multicast support in NSX, see Multicast Routing Support, Limitations, and Topology.


  1. In the vSphere Web Client, navigate to Networking & Security > NSX Edges.
  2. Double-click an NSX Edge.
  3. Click Manage > Routing > Multicast.
  4. Enable multicast.
    Version Procedure
    NSX 6.4.2 to 6.4.4

    In Configuration, click the toggle switch to enable multicast.

    NSX 6.4.5 and later
    1. Next to Configuration, click Edit.
    2. In Status, click the toggle switch to enable multicast.
  5. Configure IGMP parameters. IGMP messages are used primarily by multicast hosts to signal their interest in joining a specific multicast group, and to begin receiving group traffic. IGMP Parameters configured on the DLR must match those configured on the ESG, and have to be configured globally for the ESG and the DLR.
    IGMP Parameter Description
    Query Optional. Configures the frequency at which the designated router sends IGMP host-query messages. The default is 30 seconds. Maximum value is 3,744 seconds.
    Query Max Response Time (sec) Optional. Sets the maximum amount of time that can elapse between when the querier router sends a host-query message and when it receives a response from a host. The default is 10 seconds. Maximum value is 25 seconds.
    Last Member Query Interval (sec)

    Optional. Configures the interval at which the router sends IGMP group-specific query messages. The default is 1 second. Maximum value is 25 seconds.

    Robustness Variable Optional. The default value is 2. Maximum value is 255.
  6. (Optional) Under PIM Sparse Mode Parameters (PIM-SM), enter the Static Rendezvous Point Address. The rendezvous point (RP) is the router in a multicast network domain that acts as the root of the multicast shared tree. Packets from the upstream source and join messages from the downstream routers “rendezvous” at this core router. RP can be configured statically and dynamically with use of a Bootstrap Router (BR). If a static RP is configured, it is applicable to all the multicast groups.

    An ESG cannot be the rendezvous point or Bootstrap Candidate Router. PIM-SM configuration is done at the PIM global configuration level per edge.

  7. Under PIM Enabled Interfaces, enable PIM on an interface by clicking Configure Interfaces.
    PIM protocol must be enabled on both uplink interfaces and on a single internal interface of an ESG.
    Note: In NSX 6.4.5 or later, PIM is supported on two uplink interfaces of the Edge. However, if an NSX Edge is at 6.4.4 or earlier, PIM is supported on a single uplink interface of the Edge.
  8. Click Publish for the changes to take effect.