Operation Manual – Multicast Protocol
H3C S5500-SI Series Ethernet Switches
Chapter 1 IGMP Snooping Configuration
1-14
1.5.3 Configuring IGMP Timers
You can tune the IGMP general query interval based on actual condition of the network.
Upon receiving an IGMP query (general query or group-specific query), a host starts a
timers for each 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 IGMP query it
received). When the timer value comes down to 0, the host sends an IGMP report to the
corresponding multicast group.
An appropriate setting of the maximum response time for IGMP queries allows hosts to
respond to queries quickly and avoids burstiness of IGMP traffic on the network caused
by reports simultaneously sent by a large number of hosts when corresponding timers
expires simultaneously.
z
For IGMP general queries, you can configure the maximum response time to fill
their Max Response time field.
z
For IGMP group-specific queries, you can configure the IGMP last-member query
interval to fill their Max Response time field. Namely, for IGMP group-specific
queries, the maximum response time equals to the IGMP last-member query
interval.
I. Configuring IGMP timers globally
Follow these steps to configure IGMP timers globally:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter IGMP Snooping
view
igmp-snooping
—
Configure the maximum
response time to IGMP
general queries
max-response-time
interval
Optional
10 seconds by default
Configure the IGMP
last-member query
interval
last-member-query-inte
rval
interval
Optional
1 second by default
II. Configuring IGMP timers in a VLAN
Follow these steps to configure IGMP timers in a VLAN:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter VLAN view
vlan vlan-id
—