Signamax Managed Hardened PoE Industrial DIN-rail Mount Switch - Manual (Page 37)

7 Forwarding
32
Caution:
 Multicast source maybe doesn’t belong to the multicast group, that is to say, it is not
necessarily the receiver of multicast data;
 A multicast source can transmit packets to multiple multicast groups at the same time,
while several multicast source can also send packets to the same multicast group.
As shown in the following figure, the port 0/2 in VLAN 1 can send packets to the multicast
address 01-ac-2b-4e-32-55.
Caution: Multicast MAC address cannot configured on Link-aggregation ports.
7.3 IGMP Snooping Configuration

Note: Before configuring IGMP Snooping, first enable IGMP Snooping in 3 Advanced
Configuration .
Internet Group Management Protocol Snooping (IGMP Snooping) is a multicast constraining
mechanism that runs on Layer 2 devices to manage and control multicast groups.
By listening to and analyzing IGMP messages, a Layer 2 device running IGMP Snooping
establishes mappings between ports and multicast MAC addresses and forwards multicast
data based on these mappings.
As shown in the following figure, when IGMP Snooping is not running on the device, multicast