3Com Switch 7750 Configuration Guide

IGMP Snooping Configuration 431
Enabling IGMP Snooping You can use the command here to enable IGMP Snooping so that it can establish
and maintain MAC multicast group forwarding tables at layer 2.
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CAUTION:
■ Although both Layer 2 and Layer 3 multicast protocols can run on the same
switch simultaneously, they cannot run simultaneously on a VLAN or its
corresponding VLAN interface.
■ Before configuring IGMP Snooping in VLAN view, you must enable IGMP
Snooping globally in system view. Otherwise, the IGMP Snooping feature
cannot be enabled in VLAN view.
Configuring the Version
of IGMP Snooping
With the development of multicast technologies, IGMPv3 has found increasingly
wide application. In IGMPv3, a host can not only join a specific multicast group but
also explicitly specify to receive or reject the information from a specific multicast
source. Working with PIM-SSM, IGMPv3 enables hosts to join specific multicast
sources and groups directly, greatly simplifying multicast routing protocols and
optimizing the network topology.
Configure timers Optional “Configuring Timers” on page 432
Enable IGMP fast leave Optional “Enabling IGMP Fast Leave for a Port or
All Ports” on page 432
Configure IGMP Snooping
filter
Optional “Configuring IGMP Snooping Filtering
ACLs” on page 433
Configure to limit the number
of multicast groups on a port
Optional “Configuring to Limit Number of
Multicast Groups on a Port” on page 434
Configure IGMP Snooping
querier
Optional “Configuring IGMP Snooping Querier”
on page 434
Configure suppression on
IGMP host report messages
Optional “Configuring Suppression on IGMP Host
Report Messages” on page 435
Configure simulated joining Optional “Configuring IGMP Snooping Simulated
Joining” on page 436
Configure multicast VLAN Optional “Configuring Multicast VLAN” on page
437
Table 336 IGMP Snooping configuration tasks
Operation Description Related section
Table 337 Enable IGMP Snooping
Operation Command Description
Enter system view system-view -
Enable IGMP Snooping
globally
igmp-snooping enable Required
IGMP Snooping is disabled
globally.
Enter VLAN view vlan vlan-id -
Enable IGMP Snooping on the
VLAN
igmp-snooping enable Required
By default, IGMP Snooping is
disabled on the VLAN.