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Configuring IGMP query and response parameters on an interface
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view.
interface
interface-type
interface-number
N/A
3.
Configure the IGMP querier's
robustness variable.
igmp robust-count
robust-value
2 by default.
A higher robustness variable
makes the IGMP querier more
robust, but results in longer
multicast group timeout time.
4.
Configure the startup query
interval.
igmp startup-query-interval
interval
By default, the startup query
interval is one-quarter of the "IGMP
general query interval."
5.
Configure the startup query
count.
igmp startup-query-count
value
By default, the startup query count
is the same as the IGMP querier's
robustness variable.
6.
Configure the IGMP general
query interval.
igmp timer query
interval
60 seconds by default.
7.
Configure the maximum
response time for IGMP
general queries.
igmp max-response-time
interval
10 seconds by default.
8.
Configure the IGMP last
member query interval.
igmp last-member-query-interval
interval
1 second by default.
9.
Configure the other querier
present interval.
igmp timer other-querier-present
interval
By default, the other querier
present interval is [ IGMP general
query interval ] × [ IGMP
robustness variable ] + [ maximum
response time for IGMP general
queries ] / 2.
Enabling IGMP fast-leave processing
In some applications, such as ADSL dial-up networking, only one multicast receiver host is attached to a
port of the IGMP querier. To allow fast response to the leave messages of the host when it switches
frequently from one multicast group to another, you can enable IGMP fast-leave processing on the IGMP
querier.
With fast-leave processing enabled, after receiving an IGMP leave message from a host, the IGMP
querier directly sends a leave notification to the upstream without sending IGMP group-specific queries
or IGMP group-and-source-specific queries. Thus, the leave latency is reduced on one hand, and the
network bandwidth is saved on the other hand.
The IGMP fast-leave processing configuration is effective only if the device is running IGMPv2 or
IGMPv3.
Enabling IGMP fast-leave processing globally
Step
Command
Remarks
1.
Enter system view.
system-view
N/A