Operation Manual – Multicast
H3C S5600 Series Ethernet Switches
Chapter 3 IGMP Configuration
3-8
command, the current IGMP querier is considered to be down. In this case, a new
IGMP querier election process takes place.
IV. The maximum response time of IGMP general query messages
When the host receives a general query message, it will set a timer for each of its
multicast groups. The timer value is selected from 0 to the maximum response time at
random. When the value of a timer decreases to 0, the host will send the membership
information of the multicast group.
By configuring reasonable maximum response time, you can enable the host to
respond to the query information quickly and enable the Layer 3 switch to understand
the membership information of multicast groups quickly.
Follow these steps to configure options related to IGMP query messages:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter interface view
interface interface-type
interface-number
—
Configure the query
interval (interval of
sending general queries)
igmp timer query
seconds
Optional
60 seconds by default.
Configure the interval of
sending IGMP
group-specific query
messages
igmp
lastmember-queryinterv
al
seconds
Optional
1 second by default
Configure the number of
times of sending IGMP
group-specific query
messages
igmp robust-count
robust-value
Optional
2 by default.
Configure the other
querier present timer
igmp timer
other-querier-present
seconds
Optional
The system default is 120
seconds, namely twice
the query interval.
Configure the maximum
response time of IGMP
general queries
igmp
max-response-time
seconds
Optional
10 seconds by default.
3.2.5 Configuring the Maximum Allowed Number of Multicast Groups
By configuring the maximum number of IGMP multicast groups allowed to be joined on
an interface of the switch, you can control the number of programs on demand
available for users attached to the interface, thus to control the bandwidth usage on the
interface.