H3C S7500 Series Ethernet Switches Command Manual

Table Of Contents
Command Manual – Multicast
H3C S7500 Series Ethernet Switches Chapter 5
IGMP Configuration Commands
5-13
Examples
# Enable suppression on Layer 3 multicast IGMP report messages on the switch.
<H3C> system-view
System View: return to User View with Ctrl+Z.
[H3C] multicast routing-enable
[H3C] igmp report-aggregation
5.1.13 igmp robust-count
Syntax
igmp robust-count robust-value
undo igmp robust-count
View
VLAN interface view
Parameters
robust-value: IGMP robust value, times of sending the IGMP group-specific query
messages after the IGMP querier receives the IGMP Leave message from the host. It is
in the range of 2 times to 5 times.
Description
Use the igmp robust-count command to set the times of sending the IGMP group
query message after the IGMP query router receives the IGMP Leave message from
the host.
Use the undo igmp robust-count command to restore the default value.
By default, an IGMP querier sends IGMP group-specific query messages twice.
In the shared network, that is, a same network segment including multiple hosts and
multicast routers, the query router is responsible for maintaining the IGMP group
membership on the interface. When an IGMPv2 host leaves a group, it sends an IGMP
Leave message. When receiving the IGMP Leave message, the IGMP query router
must send the IGMP group-specific query message for specified times (by the
robust-value argument in the igmp robust-count command, with default value as 2) in
a specified time interval (by the seconds argument in the igmp
lastmember-queryinterval command, with default value as 1 second). If other hosts
interested in the specific group receive the IGMP group-specific query messages from
the IGMP query router, they will send back the IGMP Membership Report messages
within the specified maximum response time. If it receives the IGMP Membership
Report messages within the defined period (equal to robust-value × seconds), the
IGMP query router continues to maintain the membership of this group. When receiving
no IGMP Membership Report message from any host within the defined period, the