H3C Technologies H3C S7500E Series Switches - Manual (Page 273)

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present, the Layer 2 switch will act as the MLD querier to send periodic MLD queries, thus
allowing multicast forwarding entries to be established and maintained at the data link layer.
Follow these steps to enable the MLD snooping querier:
To do... Use the command... Remarks
Enter system view system-view —
Enter VLAN view vlan vlan-id —
Enable the MLD snooping
querier
mld-snooping querier
Required
Disabled by default
It is meaningless to configure an MLD snooping querier in an IPv6 multicast network running
MLD. Although an MLD snooping querier does not take part in MLD querier elections, it may
affect MLD querier elections because it sends MLD general queries with a low source IPv6
address.
For details about MLD querier, see MLD Configuration of the IP Multicast Configuration Guide.
Configuring MLD Queries and Responses
You can tune the MLD general query interval based on actual condition of the network.
Upon receiving an MLD query (general query or multicast-address-specific query), a host starts
a timer for each IPv6 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 MLD query it received). When the timer
value comes down to 0, the host sends an MLD report to the corresponding IPv6 multicast
group.
An appropriate setting of the maximum response time for MLD queries allows hosts to respond
to queries quickly and avoids bursts of MLD traffic on the network caused by reports
simultaneously sent by a large number of hosts when the corresponding timers expire
simultaneously.
z For MLD general queries, you can configure the maximum response time to fill their Max
Response time field.
z For MLD multicast-address-specific queries, you can configure the MLD last-member query
interval to fill their Max Response time field. Namely, for MLD multicast-address-specific
queries, the maximum response time equals to the MLD last-member query interval.
Configuring MLD queries and responses globally
Follow these steps to configure MLD queries and responses globally: