The primary component involved in the data plane of the transport nodes is the NSX Virtual Distributed Switch (N-VDS). On ESXi hypervisors, the N-VDS implementation is derived from VMware vSphere® Distributed Switch™ (VDS). With KVM hypervisors, the N-VDS implementation is derived from the Open vSwitch (OVS).

The N-VDS is required on NSX-T overlay and VLAN-backed networks.

The NVDS forwards traffic between:
  • Components running on the transport node (for example, between virtual machines).

  • Internal components and the physical network.

If N-VDS is used to forward traffic between internal components and physical network, the NVDS must own one or more physical interfaces (pNICs) on the transport node. As with other virtual switches, an N-VDS cannot share a physical interface with another N-VDS, it may coexist with another N-VDS (or other vSwitch) when using a separate set of pNICs. While N-VDS behavior in realizing connectivity is identical regardless of the specific implementation, data plane realization and enforcement capabilities differ based on compute manager and associated hypervisor capability.

By default, IGMP snooping (IGMPv1/v2/v3, MLDv1/v2) is enabled on N-VDS configured on an ESXi host.

To change settings of IGMP snooping on an N-VDS switch, run the following CLI commands.

get host-switch nvds mcast-filter

set host-switch nvds mcast-filter
    legacy mcast filter mode: {legacy|snooping}
     snooping mcast filter mode: {legacy|snooping}    

To change settings at a per-port level, run the following CLI commands.

get host-switch <host-switch-name> dvport <dvport-id> mcast-filter

get host-switch <host-switch-name> dvport <dvport-id> mcast-filter <entry-mode> <entry-group>

For more details, see the NSX-T Data Center Command-Line Interface Reference.