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Configuring parameters for IGMP queries and responses
CAUTION:
To avoid mistakenly deleting multicast group members, make sure the IGMP general query interval
is greater than the maximum response time for IGMP general queries.
You can modify the IGMP general query interval based on the actual condition of the network.
A receiver host starts a timer for each multicast group that it has joined when it receives an IGMP
query (general query or group-specific query). This timer is initialized to a random value in the range
of 0 to the maximum response time advertised in the IGMP query. When the timer value decreases to
0, the host sends an IGMP report to the multicast group.
To speed up the response of hosts to IGMP queries and to avoid simultaneous timer expirations
which cause IGMP report traffic bursts, you must correctly set the maximum response time.
•
The maximum response time for IGMP general queries is set by the
max-response-time
command.
•
The maximum response time for IGMP group-specific queries equals the IGMP last member
query interval, which is set by the
last-member-query-interval
interval
command.
You can configure the parameters globally for all VLANs in IGMP-snooping view or for a VLAN in
VLAN view. For a VLAN, the VLAN-specific configuration takes priority over the global configuration.
Configuring the global parameters for IGMP queries and responses
Step Command Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IGMP-snooping view.
igmp-snooping
N/A
3.
Set the maximum response
time for IGMP general
queries.
max-response-time interval
The default setting is 10
seconds.
4.
Set the IGMP last member
query interval.
last-member-query-interval
interval
The default setting is 1
second.
Configuring the parameters for IGMP queries and responses in a VLAN
Step Command Remarks
1.
Enter system view.
system-view
N/A
2.
Enter VLAN view.
vlan vlan-id
N/A
3.
Set the IGMP general query
interval in the VLAN.
igmp-snooping query-interval
interval
The default setting is 125
seconds.
4.
Set the maximum response
time for IGMP general
queries in the VLAN.
igmp-snooping max-response-time
interval
The default setting is 10
seconds.
5.
Set the IGMP last member
query interval in the VLAN.
igmp-snooping
last-member-query-interval
interval
The default setting is 1
second.
Configuring parameters for IGMP messages
This section describes how to configure parameters for IGMP messages.