H3C Technologies H3C S12500 Series Switches - Manual (Page 370)

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• For MLD general queries, the maximum response delay is set by the max-response-time command.
• For MLD multicast-address-specific query and multicast-address-and-source-specific query
messages, the maximum response delay equals the last listener query interval.
When multiple multicast routers exist on the same subnet, the MLD querier is responsible for sending MLD
query messages. If a non-querier router receives no MLD query from the querier when the other querier
present timer expires, it considers the querier has failed and starts a new querier election. Otherwise, the
non-querier resets the other querier present timer.
IMPORTANT:
•
To avoid frequent MLD querier changes, set the other querier present interval greater than the MLD
query interval.
• To avoid mistakenly remove multicast group member, set the MLD query interval greater than the
maximum response delay for MLD general queries.
Configuring MLD query and response parameters globally
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter MLD view. mld N/A
3. Configure the MLD querier's
robustness variable.
robust-count robust-value
2 by default.
A higher robustness variable
makes the MLD querier more
robust but results in a longer IPv6
multicast group timeout time.
4. Configure the startup query
interval.
startup-query-interval interval
By default, the startup query
interval is one-quarter of the "MLD
query interval."
5. Configure the startup query
count.
startup-query-count value
By default, the startup query count
is the same as the MLD querier's
robustness variable.
6. Configure the MLD query
interval.
timer query interval 125 seconds by default.
7. Configure the maximum
response delay for MLD
general query messages.
max-response-time interval 10 seconds by default.
8. Configure the MLD last
listener query interval.
last-listener-query-interval interval 1 second by default.
9. Configure the MLD other
querier present interval. timer other-querier-present
interval
By default, the other querier
present interval is determined by
the formula "Other querier present
interval (in seconds) = [ MLD query
interval ] × [ MLD querier's
robustness variable ] + [ maximum
response delay for MLD general
query ] / 2."