HP 6125G - Configuring IGMP Report Suppression; Setting the Maximum Number of Multicast Groups that a Port Can Join

29
Configuring IGMP report suppression
When a Layer 2 switch receives an IGMP report from a multicast group member, the switch forwards the
message to the Layer 3 device that directly connects to the Layer 2 switch. When multiple members of a
multicast group are attached to the Layer 2 switch, the Layer 3 device might receive duplicate IGMP
reports for the multicast group from these members.
With the IGMP report suppression function enabled, within each query interval, the Layer 2 switch
forwards only the first IGMP report for the multicast group to the Layer 3 device. It does not forward the
subsequent IGMP reports for the same multicast group. This helps reduce the number of packets being
transmitted over the network.
IMPORTANT:
On an IGMP snooping proxy, IGMP membership reports are suppressed if the entries for the
correspondin
g
g
roups exist in the forwardin
g
table, no matter the suppression function is enabled or not.
To configure IGMP report suppression:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter IGMP-snooping view.
igmp-snooping N/A
3. Enable IGMP report
suppression.
report-aggregation Enabled by default
Setting the maximum number of multicast groups that a port can
join
To regulate multicast traffic on a port, configure the maximum number of multicast groups that the port
can join.
When you configure this maximum number, if the number of multicast groups the port has joined exceeds
the configured maximum value, the system deletes all the forwarding entries for the port from the IGMP
snooping forwarding table, and the hosts on this port join multicast groups again until the number of
multicast groups that the port joins reaches the maximum value. When the port joins a multicast group,
if the port has been configured as a static member port, the system applies the configurations to the port
again. If you have configured simulated joining on the port, the system establishes corresponding
forwarding entry for the port after receiving a report from the simulated member host.
To set the maximum number of multicast groups that a port can join:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
interface interface-type
interface-number
Use either command.
3. Set the maximum number of
multicast groups that a port
can join.
igmp-snooping group-limit limit
[ vlan vlan-list ]
2000 by default.