3Com Switch 7750 Configuration Guide Guide

390 CHAPTER 40: IGMP SNOOPING CONFIGURATION
IGMP Snooping
Configuration
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.
c
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 Timers This configuration task is to manually configure the aging timer of the router port,
the aging timer of the multicast member ports, and the query response timer.
■ If the switch receives no general IGMP query message from a router within the
aging time of the router port, the switch removes the router port from the port
member lists of all MAC multicast groups.
■ If the switch receives no IGMP host report message, it sends an IGMP
group-specific query packet to the port and enable the query response timer of
the IP multicast group.
Tabl e 306 IGMP Snooping configuration tasks
Operation Description Related section
Enable IGMP Snooping Required “Enabling IGMP Snooping”
Configure timers Optional “Configuring Timers”
Enable IGMP fast leave Optional
“Enabling IGMP Fast Leave for a Port or All
Ports”
Configure IGMP Snooping
filter
Optional
“Configuring IGMP Snooping Filtering
ACLs”
Configure to limit the number
of multicast groups on a port
Optional
“Configuring to Limit Number of Multicast
Groups on a Port”
Configure suppression on
IGMP host report packets
Optional
“Configuring Suppression on IGMP Host
Report Packets”
Configure multicast VLAN Optional “Configuring Multicast VLAN”
Tabl e 307 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.