Operation Manual – MulticastH3C S7500 Series Ethernet Switches Chapter 3 IGMP Snooping Configuration3-103.2.5 Configuring to Limit the Number of Multicast Groups on a PortWith limit imposed on the number of multicast groups on a switch port, users can nolonger have as many multicast groups as they want when demanding programs inmulticast groups. Thereby, the bandwidth on the port is controlled.Follow these steps to configure to limit number of multicast groups on a port:To do... Use the command... RemarksEnter system view system-view —Enter Ethernet portviewinterface interface-typeinterface-number —Limit the number ofmulticast groups on aportigmp-snooping group-limitlimit [ vlan vlan-list[ overflow-replace ] |overflow-replace]OptionalThe number of multicastgroups on a port is notlimited by default.3.2.6 Configuring Suppression on IGMP Report MessagesWhen a Layer 2 switch receives IGMP report messages from a host in a multicastgroup, the switch will forward the packets to the port of a Layer 3 switch that isconnected to it. In this way, a Layer 3 switch will receive the same IGMP reportmessages from multiple hosts in a multicast group when there are multiple hosts in thismulticast group.When suppression on IGMP report messages is enabled, in a query interval, the Layer2 switch will forward only the first IGMP report message from a multicast group to theLayer 3 switch, and drop the other IGMP report messages from the same multicastgroup.Follow these steps to configure suppression on IGMP report messages:To do... Use the command... RemarksEnter system view system-view —Configuresuppression on IGMPreport messagesreport-aggregationRequiredBy default, suppression on IGMPreport messages is disabled.3.2.7 Configuring Multicast VLANIn the current multicast mode, when users in different VLANs order the same stream,the multicast stream is copied to each of the VLANs. This mode wastes a lot ofbandwidth.
