Tp-Link TL-SG3216 [103/236] Snooping config

The host, running IGMPv1, does not send IGMP leave message when leaving a multicast group,

as a result, the switch can not get the leave information of the host momentarily. However, after

leaving the multicast group, the host does not send IGMP report message any more, so the switch

will remove the port from the corresponding multicast address table when its member port time

times out. The host, running IGMPv2 or IGMPv3, sends IGMP leave message when leaving a

multicast group to inform the multicast router of its leaving.

When receiving IGMP leave message, the switch will forward IGMP group-specific-query message

to check if other members in the multicast group of the port need this multicast and reset the

member port time to the leave time. When the leave time times out, the switch will remove the port

from the corresponding multicast group. If no other member is in the group after the port is

removed, the switch will remove the whole multicast group and send IGMP leave message to the

router.

¾ IGMP Snooping Fundamentals

1. Ports

Router Port: Indicates the switch port directly connected to the multicast router.

Member Port: Indicates a switch port connected to a multicast group member.

2. Timers

Router Port Time: Within the time, if the switch does not receive IGMP query message from the

router port, it will consider this port is not a router port any more. The default value is 300 seconds.

Member Port Time: Within the time, if the switch does not receive IGMP report message from the

member port, it will consider this port is not a member port any more. The default value is 260

seconds.

Leave Time: Indicates the interval between the switch receiving a leave message from a host and

the switch removing the host from the multicast groups. The default value is 1 second.

The IGMP Snooping function can be implemented on Snooping Config, Port Config, VLAN

Config and Multicast VLAN pages.

8.1.1 Snooping Config

To configure the IGMP Snooping on the switch, please firstly configure IGMP global configuration

and related parameters on this page.

If the multicast address of the received multicast data is not in the multicast address table, the

switch will broadcast the data in the VLAN. When Unknown Multicast Discard feature is enabled,

the switch drops the received unknown multicast so as to save the bandwidth and enhance the

process efficiency of the system. Please configure this feature appropriate to your needs.

Choose the menu Multicast→IGMP Snooping→Snooping Config to load the following page.