Configuring L2 Multicast Features 803
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Configuring L2 Multicast Features
This chapter describes the layer 2 multicast features on the Dell Networking
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
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