6-14It is not recommended to configure this function while the multicast VLAN function is in effect.Configuring Multicast VLANIn traditional multicast implementations, when users in different VLANs listen to the same multicastgroup, the multicast data is copied on the multicast router for each VLAN that contains receivers. This isa big waste of network bandwidth.In an IGMP Snooping environment, by configuring a multicast VLAN and adding ports to the multicastVLAN, you can allow users in different VLANs to share the same multicast VLAN. This saves bandwidthbecause multicast streams are transmitted only within the multicast VLAN. In addition, because themulticast VLAN is isolated from user VLANs, this method also enhances the information security.Multicast VLAN is mainly used in Layer 2 switching, but you must make the correspondingconfigurations on the Layer 3 switch.Follow these steps to configure multicast VLAN on the Layer 3 switch:To do... Use the command... RemarksEnter system view system-view —Create a multicast VLAN andenter VLAN view vlan vlan-id —Return to system view quit —Enter VLAN interface view interface Vlan-interfacevlan-id —Enable IGMP igmp enableRequiredBy default, the IGMP feature isdisabled.Return to system view quit —Enter Ethernet port view for theLayer 2 switch to be configuredinterface interface-typeinterface-number —Define the port as a trunk orhybrid port port link-type { trunk | hybrid } Requiredport hybrid vlan vlan-id-list{ tagged | untagged }Specify the VLANs to beallowed to pass the Ethernetport port trunk permit vlan vlan-listRequiredThe multicast VLAN defined onthe Layer 2 switch must beincluded, and the port must beconfigured to forward taggedpackets for the multicast VLANif the port type is hybrid.Follow these steps to configure multicast VLAN on the Layer 2 switch:To do... Use the command... RemarksEnter system view system-view —Enable IGMP Snooping igmp-snooping enable —
