Igmp Proxy; Figure 75 Igmp Proxy Message Flow Example - ZyXEL Communications IES-1248-51V User Manual

Chapter 20 IGMP
The IES forwards multicast traffic destined for multicast groups (that it has
learned from IGMP snooping or that you have manually configured) to ports that
are members of that group. The IES discards multicast traffic destined for
multicast groups that it does not know. IGMP snooping generates no additional
network traffic, allowing you to significantly reduce multicast traffic passing
through your device.

20.2.2 IGMP Proxy

IGMP Proxy is a feature in the IES that allows for the reduction of multicast traffic
from an 'upstream' multicast server to 'downstream' host devices.
In IGMP proxy, an upstream interface is the port that is closer to the source (or
the multicast server) and is able to receive multicast traffic. A downstream
interface is a port that connects to a host (such as a computer).
The following figure shows a network example where A is the multicast server
while the computers labled 1, 2 and 3 are the receiving hosts. In the figure, A is
connected to the upstream interface (B) and 1, 2 and 3 are connected to the
downstream interface (C).
Note: In daisychain mode, Ethernet interface 1 is set as the upstream interface and
Ethernet interface 2 and the DSL ports are set as downstream interfaces.

Figure 75 IGMP Proxy Message Flow Example

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A
B
C
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