3Com Switch 8800 Advanced Software V5 Configuration Guide

548 CHAPTER 41: IGMP SNOOPING CONFIGURATION
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■ Each simulated host is equivalent to an independent host. For example, when
receiving an IGMP query, the simulated host corresponding to each
configuration responds respectively.
■ The IGMP version of a simulated host is the same as the IGMP Snooping
version current running on the switch.
Enabling the Fast Leave
Feature
By default, when receiving a group-specific IGMP leave message on a port, the
switch first sends an IGMP group-specific query message that port, rather than
directly deleting the port from the multicast forwarding table. If the switch
receives no IGMP reports within a certain period of waiting time, it deletes the
port from the forwarding table.
With the fast leave feature enabled, when the switch receives a group-specific
IGMP leave message on a port, the switch directly deletes this port from the
forwarding table without first sending an IGMP group-specific query to the port. If
only one host is attached to the port, enable the fast leave feature to improve
bandwidth and resource usage.
Configuring the fast leave feature globally
Follow these steps to configure the fast leave feature globally:
Configuring the fast leave feature on a port or a group ports
Follow these steps to configure the fast leave feature on a port or a group ports:
c
CAUTION: If the fast leave feature is enabled on a port to which more than one
host is attached, when one host leaves a multicast group, the other hosts attached
Configure simulated (*, G) or (S, G) joining igmp-snooping
host-join
group-address [
source-ip
source-address ] vlan
vlan-id
Required
Disabled by default
To do... Use the command... Remarks
To do... Use the command... Remarks
Enter system view system-view -
Enter IGMP Snooping view igmp-snooping -
Enable the fast leave feature fast-leave [ vlan vlan-list ] Required
Disabled by default
To do... Use the command... Remarks
Enter system view system-view -
Enter the
correspon
ding view
Enter Ethernet
interface view
interface interface-type
interface-number
Use either command
Enter interface
group view
port-group { manual
port-group-name |
aggregation agg-id }
Enable the fast leave feature igmp-snooping fast-leave [
vlan vlan-list ]
Required
Disabled by default