Chapter 17 IGMP

In IGMP proxy, an upstream interface is the port that is closer to the source (or the root of the multicast tree) and is able to receive multicast traffic. There should only be one upstream interface (also known as the query port) for one query VLAN on the IES-612-51A. 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 source while computers 1, 2 and 3 are the receivers. In the figure A is connected to the upstream interface and 1, 2 and 3 are connected to the downstream interface.

Figure 68 IGMP Proxy Network Example

The IES-612-51A will not respond to IGMP join and leave messages on the upstream interface. The IES-612-51A only responds to IGMP query messages on the upstream interface. The IES-612-51A sends IGMP query messages to the hosts that are members of the query VLAN.

The IES-612-51A only sends an IGMP leave messages via the upstream interface when the last host leaves a multicast group.

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.

17.3 IGMP Status Screen

Use this screen to view current IGMP information.

To open this screen, click Advanced Application, IGMP.

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IES-612-51A User’s Guide