Users Guide

Layer-2 Multicast Features 957

Layer-2 Multicast Features

Dell EMC Networking N-Series Switches

This chapter describes the Layer-2 (L2) multicast features on the Dell EMC

Networking N-Series switches. The features this chapter describes include

bridge multicast flooding and forwarding, Internet Group Management

Protocol (IGMP) snooping, Multicast Listener Discovery (MLD) snooping,

and Multicast VLAN Registration (MVR).

The topics covered in this chapter include:

• L2 Multicast Overview

• Snooping Switch Restrictions

• Default L2 Multicast Values

• Configuring L2 Multicast Features (Web)

• Configuring L2 Multicast Features (CLI)

• Case Study on a Real-World Network Topology

L2 Multicast Overview

Multicast traffic is traffic from one source that has multiple destinations. The

L2 multicast features on the switch help control network flooding of Ethernet

multicast and IP multicast traffic by keeping track of multicast group

membership. It is essential that a multicast router be connected to a Dell

EMC Networking Layer-2 multicast switch for IGMP/MLD snooping to

operate properly. The presence of a multicast router allows the snooping

switch to relay IGMP reports to the router and to forward multicast data

sources to the multicast router as well as restrict flooding of multicast sources

in a VLAN.

Multicast Flooding and Forwarding

Flooding behavior is to send incoming multicast packets to all ports in the

VLAN other than the ingress port. Forwarding behavior is to send incoming

multicast packets to selected ports in the VLAN. Forwarding behavior is