1-14Before configuring an IGMP Snooping policy, prepare the following data:z ACL rule for multicast group filteringz The maximum number of multicast groups that can pass the portsConfiguring a Multicast Group FilterOn an IGMP Snooping–enabled switch, 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 switch checks the report against the configured ACLrule. If the port on which the report was received can join this multicast group, the switch adds an entryfor this port in the IGMP Snooping forwarding table; otherwise the switch drops this report message.Any multicast data that has failed the ACL check will not be sent to this port. In this way, the serviceprovider can control the VOD programs provided for multicast users.Configuring a multicast group filter globallyFollow these steps to configure a multicast group filter globally:To do... Use the command... RemarksEnter system view system-view —Enter IGMP Snooping view igmp-snooping —Configure a multicast groupfiltergroup-policy acl-number[ vlan vlan-list ]RequiredBy default, no group filter isglobally configured, that is,hosts in VLANs can join anyvalid multicast group.Configuring a multicast group filter on a port or a group of portsFollow these steps to configure a multicast group filter on a port or a group of ports:To do... Use the command... RemarksEnter system view system-view —interface interface-typeinterface-numberEnter Ethernet port/Layer 2aggregate port view or portgroup view port-group manualport-group-nameRequiredUse either approachConfigure a multicast groupfilterigmp-snooping group-policyacl-number [ vlan vlan-list ]RequiredBy default, no group filter isconfigured on the current port,that is, hosts on this port canjoin any valid multicast group.Configuring Multicast Source Port FilteringWith the multicast source port filtering feature enabled on a port, the port can be connected withmulticast receivers only rather than with multicast sources, because the port will block all multicast datapackets while it permits multicast protocol packets to pass.
