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DGS-3400 Series Layer 2 Gigabit Ethernet Managed Switch CLI Manual
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IGMP
AND
MLD
S
NOOPING
C
OMMANDS
The Internet Group Management Protocol (IGMP) is a Layer 2 or Layer 3 protocol used to manage the membership of
Internet Protocol multicast groups. IGMP is used by IP hosts and adjacent multicast routers to establish multicast group
memberships. IGMP snooping, as implied by the name, is a feature that allows a Layer 2 switch to "listen in" on the IGMP
conversation between hosts and routers by processing the Layer 2 or Layer 3 IGMP packets sent in a multicast network.
The Multicast Listener Discovery (MLD) is protocol used by an IPv6 router to discover the presence of multicast listeners
(that is, nodes wishing to receive multicast packets) on its directly attached links, and to discover specifically which
multicast addresses are of interest to those neighboring nodes.
The IGMP and MLD Snooping commands in the Command Line Interface (CLI) are listed (along with the appropriate
parameters) in the following table.