User Manual
496
Users Manual of XGS-6350-24X4C
minimum IP address is the querier in the network. The switch that is not the querier needs to save a clock to
record the existence of the querier. If the clock times out, the non-querier switch turns to be the querier until it
receives the IGMP Query message from the switch with a smaller IP address.
For IGMP-Router V2, you can configure other querier intervals using the following command:
Command Purpose
ip igmpquerier-timeouttime
Configures the interval for other queriers
(unit: second).
For IGMP-Router V1, the interval of other queriers is useless. For IGMP-Router V3, the interval cannot be
configured because it is decided by the protocol itself.
50.3.2.4 Configuring Maximum IGMP Response Time
For IGMP-Router V2 and IGMP-Router V3, special data field in the transmitted IGMP General Query
message regulates the maximum response time of the IGMP host. That is, the IGMP host has to send the
response message before the regulated maximum response time expires, indicating that the General Query
message is received. If the maximum response time is set to a big value, the change of multicast group
members delays. If the maximum response time is set to a small value, the flow of the IGMP message will be
increased in the current network.
The maximum IGMP r
esponse time must be shorter than the IGMP query interval. If
the value of the maximum response time is bigger than the query interval, the
system will automatically set the maximum response time to query-interval – 1.
For IGMP-Router V2 and IGMP-Router V3, run the following command in interface configuration mode to set
the maximum IGMP response time:
Command Purpose
ip igmp
query-max-response-timetime
Configures the maximum IGMP
response time (unit: second).
For IGMP-Router V1, the maximum IGMP response time is decided by the protocol itself. Therefore, the
previous command is useless to IGMP-Router V1.
50.3.2.5 Configuring IGMP Query Interval for the Last Group Member
For IGMP-Router V2 and IGMP-Router V3, When the Group Specific Query message for a specific multicast
group is sent, the query interval of the last group member will be used as the maximum response time of the
host. That is, the IGMP host has to send the response message before the maximum response time of the
last group member expires, indicating that the Group Specific Query message is received. If the IGMP host
finds that it need not respond to the query message, it will not respond to the message after the interval. In
this case, the multicast switch is to update the saved multicast group member information. If the query interval
of the last group member is set to a big value, the change of the multicast group member delays. If the query
interval of the last group member is set to a small value, the flow of the IGMP message is to increase in the
current network.