Configuring Basic Functions of IGMP Snooping 559Configuring BasicFunctions of IGMPSnoopingConfigurationPrerequisitesBefore configuring the basic functions of IGMP Snooping, complete the followingtask:■ Configure the corresponding VLANs.Before configuring the basic functions of IGMP Snooping, prepare the followingdata:■ Version of IGMP Snooping.Enabling IGMP Snooping Follow these steps to enable IGMP Snooping:n ■ IGMP Snooping must be enabled globally before it can be enabled in a VLAN.■ After enabling IGMP Snooping in a VLAN, you cannot enable IGMP and/or PIMon the corresponding VLAN interface, and vice versa.■ When you enable IGMP Snooping in a specified VLAN, this function takeseffect for Ethernet ports in this VLAN only.Configuring the Versionof IGMP SnoopingBy configuring an IGMP Snooping version, you actually configure the version ofIGMP messages that IGMP Snooping can process.■ IGMP Snooping version 2 can process IGMPv1 and IGMPv2 messages, but notIGMPv3 messages, which will be flooded in the VLAN.■ IGMP Snooping version 3 can process IGMPv1, IGMPv2 and IGMPv3 messages.Follow these steps to configure the version of IGMP Snooping:c CAUTION: If you switch IGMP Snooping from version 3 to version 2, the systemwill clear all IGMP Snooping forwarding entries from dynamic joins, and willTo do… Use the command… RemarksEnter system view system-view -Enable IGMP Snoopingglobally and enterIGMP-Snooping viewigmp-snooping RequiredDisabled by defaultReturn to system view quit -Enter VLAN view vlan vlan-id -Enable IGMP Snooping in theVLANigmp-snooping enable RequiredDisabled by defaultTo do… Use the command… RemarksEnter system view system-view -Enter VLAN view vlan vlan-id -Configure the version of IGMPSnoopingigmp-snooping versionversion-numberOptionalVersion 2 by default
