2-7Enabling fast leave processing in Ethernet port viewFollow these steps to enable fast leave processing in Ethernet view:To do… Use the command… RemarksEnter system view system-view —Enter Ethernet port view interface interface-typeinterface-number —Enable fast leave processingfor specific VLANsigmp-snooping fast-leave[ vlan vlan-list ]RequiredBy default, the fast leaveprocessing feature is disabled.z The fast leave processing function works for a port only if the host attached to the port runs IGMPv2or IGMPv3.z The configuration performed in system view takes effect on all ports of the device if no VLAN isspecified; if one or more VLANs are specified, the configuration takes effect on all ports in thespecified VLAN(s).z The configuration performed in Ethernet port view takes effect on the port no matter which VLAN itbelongs to if no VLAN is specified; if one or more VLANs are specified, the configuration takeseffect on the port only if the port belongs to the specified VLAN(s).z If fast leave processing and unknown multicast packet dropping are enabled on a port to whichmore than one host is connected, when one host leaves a multicast group, the other hostsconnected to port and interested in the same multicast group will fail to receive multicast data forthat group.Configuring a Multicast Group FilterOn an IGMP Snooping-enabled device, the configuration of a multicast group allows the serviceprovider to define restrictions on multicast programs available to different users.In an actual application, when a user requests a multicast program, the user’s host initiates an IGMPreport. Upon receiving this report message, the device checks the report against the ACL ruleconfigured on the receiving port. If the receiving port can join this multicast group, the device adds thisport to the IGMP Snooping multicast group list; otherwise the device drops this report message. Anymulticast data that has failed the ACL check will not be sent to this port. In this way, the service providercan control the VOD programs provided for multicast users.Make sure that an ACL rule has been configured before configuring this feature.
