H3C Technologies H3C SecPath F1000-E - Manual (Page 48)

14
To do... Use the command... Remarks
Configure the startup query count
igmp startup-query-count
value
Optional
For the system default, see “Note”
below.
Configure the IGMP general query
interval
igmp timer query interval
Optional
60 seconds by default
Configure the IGMP querier
robustness variable
igmp robust-count robust-value
Optional
2 by default
Configure the maximum response
time for IGMP general queries igmp max-response-time
interval
Optional
10 seconds by default
Configure the IGMP last member
query interval
igmp
last-member-query-interval
interval
Optional
1 second by default
Configure the other querier present
interval igmp timer
other-querier-present interval
Optional
For the system default, see “Note”
below.
NOTE:
•
If not statically configured, the startup query interval is 1/4 of the “IGMP general query interval”. By
default, the IGMP general query interval is 60 seconds, so the startup query interval = 60 / 4 = 15
(seconds).
• If not statically configured, the startup query count is set to the IGMP querier robustness variable. By
default, the IGMP querier robustness variable is 2, so the startup query count is also 2.
• If not statically configured, the other querier present interval is [ IGMP general query interval ] times
[ IGMP robustness variable ] plus [ maximum response time for IGMP general queries ] divided by two.
The default values of these three parameters are 60 (seconds), 2 and 10 (seconds) respectively, so the
other querier present interval = 60 × 2 + 10 / 2 = 125 (seconds).
• If statically configured, the startup query interval, the startup query count, and the other querier present
interval take the configured values.
CAUTION:
•
Make sure that the other querier present interval is greater than the IGMP general query interval;
otherwise the IGMP querier may change frequently on the network.
• Make sure that the IGMP general query interval is greater than the maximum response time for IGMP
general queries; otherwise, multicast group members may be wrongly removed.
• The configurations of the maximum response time for IGMP general queries, the IGMP last member
query interval and the IGMP other querier present interval are effective only for IGMPv2 or IGMPv3.
Configuring 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.