IGMPv3 Configuration

introduction introduction igmpv3 enhances host control capabilities while maintaining backward compatibility with igmpv1 and igmpv2 it enables hosts to explicitly specify whether to accept or reject multicast traffic from particular sources (s) when joining a multicast group (g) the host membership report mechanism operates as follows source specific joins\ to receive traffic only from designated sources (e g , s1, s2, ), hosts send reports marked as include (s1, s2, ) to block traffic from specific sources (e g , s1, s2, ), hosts send reports marked as exclude (s1, s2, ) efficiency improvement\ a single igmpv3 membership report can carry information for multiple multicast groups, unlike earlier versions (igmpv1/v2) that required separate reports per group this significantly reduces control message overhead explanation of principles explanation of principles the destination address of an igmpv3 report message is 224 0 0 22, which can carry one or more group records each group record contains a multicast group address and a list of multicast source addresses group records can be classified into several types is in indicates that the filtering mode between the multicast group and the multicast source list is include, meaning it will only receive multicast data sent to this group from the specified source list is ex indicates that the filtering mode between the multicast group and the multicast source list is exclude, meaning it will only receive multicast data sent to this group from sources not in the specified list to in indicates a change in filtering mode from exclude to include between the multicast group and the multicast source list operation command description enter the vlan view vlan id enable igmp snooping igmp snooping enable enable igmp snooping v3 version igmp snooping version 3 configuration example configuration example the router connects to the user network through a device the network contains four users pc a, pc b, pc c, and pc d the multicast reception requirements are as follows pc a & pc b only receive multicast data for group 225 1 1 1 from source 2 1 1 1 configured with include (2 1 1 1) for group 225 1 1 1 pc c rejects multicast data for group 225 1 1 1 from source 2 1 1 1 configured with exclude (2 1 1 1) for group 225 1 1 1 pc b & pc c only receive multicast data for group 225 0 0 2 from source 3 1 1 2 configured with include (3 1 1 2) for group 225 0 0 2 procedure procedure create a vlan and enable igmp snooping sonic(config)# vlan 100 sonic(config vlan 100)# igmp snooping enable sonic(config vlan 100)# igmp snooping version 3 sonic(config)# port group ethernet 1 5 sonic(config port group 1 3)# switchport access vlan 100 pc a and pc b send join requests for multicast group 225 1 1 1 from source 2 1 1 1 pc c sends block request for multicast group 225 1 1 1 from source 2 1 1 1 pc b and pc c send join requests for multicast group 225 1 1 2 from source 3 1 1 1 verify configuration verify configuration view multicast vlan configuration sonic(config)# do show l2 multicast table total l2 multicast forwarding group counters 2 (source,group) interface vlan uvlan mode \ (3 1 1 2,225 0 0 2) ethernet6 vlan100 vlan100 incl (2 1 1 1,225 0 0 1) ethernet2 vlan100 vlan100 incl ethernet3 vlan100 vlan100 incl (0 0 0 0,225 0 0 1) ethernet4 vlan100 vlan100 incl (2 1 1 1,225 0 0 1) ethernet4 vlan100 vlan100 excl send multicast packets with destination ips 225 1 1 1 and 225 1 1 2 respectively, and verify that each pc correctly receives or blocks the multicast packets as expected