3Com Switch 7750 Configuration Guide Guide

IGMP Configuration Tasks 413
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CAUTION: When there are multiple multicast routers in a network segment, the
querier is responsible for sending IGMP query messages to all the hosts in the
network segment.
Configuring IGMP
Multicast Groups on the
Interface
You can perform the following configurations on the interface for the IGMP
multicast groups:
■ Limit the number of multicast groups
■ Limit the range of multicast groups that the interface serves
Limit the number of joined multicast groups
If the number of joined IGMP groups on the multicast routing interface of the
switch is not limited, the memory of the switch may be used out and the routing
Table 330 Configure IGMP query messages
Operation Command Description
Enter system view system-view -
Enable the multicast routing
protocol
multicast routing-enable Required
Enter VLAN interface view
interface Vlan-interface
interface-number
-
Enable IGMP on the current
interface
igmp enable
Required
By default, if the IP multicast
routing protocol is enabled
globally, IGMP is enabled on
all the layer-3 interfaces
automatically.
Configure the query interval igmp timer query seconds
Optional
The query interval is 60
seconds by default.
Configuring the interval of
sending IGMP group-specific
query packets
igmp
lastmember-queryinterval
seconds
Optional
By default, the interval of
sending IGMP group-specific
query packets is 1 second.
Configuring the times of
sending IGMP group-specific
query packets
igmp robust-count
robust-value
Optional
By default, the times of
sending IGMP group-specific
query packets is 2.
Configure the maximum
lifetime of an IGMP querier
igmp timer
other-querier-present
seconds
Optional
The lifetime of an IGMP
querier is 120 seconds by
default.
If the Layer 3 switch does not
receive query messages in two
times of the interval specified
by the igmp timer query
command, the former querier
is considered as ineffective.
Configure the maximum
IGMP query response time
igmp max-response-time
seconds
Optional
The maximum IGMP query
response time is 10 seconds.