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As shown in
, in a Layer 2–only network environment, two multicast sources Source 1 and
Source 2 send multicast data to multicast groups 224.1.1.1 and 225.1.1.1, respectively. Host A and Host C
are receivers of multicast group 224.1.1.1. Host B and Host D are receivers of multicast group 225.1.1.1.
IGMPv2 runs on all the receivers, and IGMPv2 snooping runs on all the switches. Switch A, which is close
to the multicast sources, is chosen as the IGMP snooping querier.
To prevent Switch A from flooding of unknown multicast traffic within the VLAN, be sure to configure all
the switches to drop unknown multicast data packets.
Because a switch does not enlist a port that has heard an IGMP query with a source IP address of 0.0.0.0
(default) as a dynamic router port, configure a non-all-zero IP address as the source IP address of IGMP
queries to ensure normal creation of Layer 2 multicast forwarding entries.
Figure 48
Network diagram
Configuration procedure
1.
Configure switch A:
# Enable IGMP snooping globally.
<SwitchA> system-view
[SwitchA] igmp-snooping
[SwitchA-igmp-snooping] quit
# Create VLAN 100 and assign Ethernet 1/1 through Ethernet 1/3 to the VLAN.
[SwitchA] vlan 100
[SwitchA-vlan100] port ethernet 1/1 to ethernet 1/3
# Enable IGMP snooping and the function of dropping unknown multicast traffic in VLAN 100.
[SwitchA-vlan100] igmp-snooping enable
[SwitchA-vlan100] igmp-snooping drop-unknown
# Enable the IGMP snooping querier function in VLAN 100
[SwitchA-vlan100] igmp-snooping querier
# Set the source IP address of IGMP general queries and group-specific queries to 192.168.1.1
in VLAN 100.
[SwitchA-vlan100] igmp-snooping general-query source-ip 192.168.1.1
[SwitchA-vlan100] igmp-snooping special-query source-ip 192.168.1.1