Black Box LGB1148A, LGB1126A, Managed Gigabit Switch, LGB1108A manual Igmp Snooping

Chapter 3: Configuration

3.5 IGMP Snooping

This function is used to establish the multicast groups to forward the multicast packet to the member ports, and, in doing so, avoids wasting the bandwidth while IP multicast packets are running over the network. This is because a switch that does not support IGMP or IGMP Snooping cannot tell the multicast packet from the broadcast packet, so it can only treat them all as broadcast packets. Without IGMP Snooping, the multicast packet forwarding function is plain, and nothing is different from broadcast packet.

A switch-supported IGMP Snooping, with the functions of query, report and leave, a type of packet exchanged between IP Multicast Router/Switch and IP Multicast Host, can update the information of the Multicast table when a member (port) joins or leaves an IP Multicast Destination Address. With this function, once a switch receives an IP multicast packet, it will forward the packet to the members who joined in a specified IP multicast group before.

The packets will be discarded by the IGMP Snooping if the user transmits multicast packets to the multicast group that had not been built up in advance. IGMP mode enables the switch to issue IGMP function that you enable IGMP proxy or snooping on the switch, which connects to a router closer to the root of the tree. This interface is the upstream interface. The router on the upstream interface should be running IGMP.

3.5.1 Basic Configuration

This section describes how to set the basic IGMP snooping on the switch, which connects to a router closer to the root of the tree. This interface is the upstream interface. The router on the upstream interface should be running IGMP.

Web Interface

To configure the IGMP Snooping parameters in the Web interface:

1.Click Configuration, IGMP Snooping, Basic Configuration.

2.Check to select which Global configuration to enable or disable.

3.Check which port wants to become a Router Port or enable/disable the Fast Leave function.

4.Scroll to set the Throttling parameter.

5.Click the Save button to save the setting.

6.To cancel your changes, click the Reset button to revert to previously saved values.

3-26. The IGMP Snooping Configuration screen.

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