H3C Technologies H3C S10500 Series Switches - Manual (Page 43)

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To do... Use the command... Remarks
Enable IGMP snooping querier igmp-snooping querier
Required
Disabled by default.
CAUTION:
It is meaningless to configure an IGMP snooping querier in a multicast network that runs IGMP. Although
an IGMP snooping querier does not participate in IGMP querier elections, it might affect IGMP querier
elections because it sends IGMP general queries with a low source IP address. For more information about
IGMP querier, see the chapter “IGMP configuration.”
Configuring IGMP queries and responses
You can set the IGMP general query interval based on actual conditions of the network.
After receiving an IGMP query (general query or group-specific query), a host starts a timer for each
multicast group it has joined. This timer is initialized to a random value in the range of 0 to the maximum
response time (the host obtains the value of the maximum response time from the Max Response Time
field in the IGMP query it received). When the timer value comes down to 0, the host sends an IGMP
report to the corresponding multicast group.
An appropriate setting of the maximum response time for IGMP queries allows hosts to respond to
queries quickly and avoids bursts of IGMP traffic on the network caused by reports simultaneously sent
by a large number of hosts when the corresponding timers expire simultaneously.
• For IGMP general queries, you can configure the maximum response time to fill the Max Response
time field.
• For IGMP group-specific queries, you can configure the IGMP last-member query interval to fill the
Max Response time field. Namely, for IGMP group-specific queries, the maximum response time
equals to the IGMP last-member query interval.
Configuring IGMP queries and responses globally
Follow these steps to configure IGMP queries and responses globally:
To do... Use the command... Remarks
Enter system view system-view —
Enter IGMP-snooping view igmp-snooping —
Set the maximum response time for
IGMP general queries
max-response-time interval
Required
10 seconds by default.
Set the IGMP last-member query
interval
last-member-query-interval interval
Required
1 second by default.
Configuring IGMP queries and responses in a VLAN
Follow these steps to configure IGMP queries and responses in a VLAN:
To do... Use the command... Remarks
Enter system view system-view —
Enter VLAN view vlan vlan-id —