TP-Link T3700G-28TQ, Руководство пользователя

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is not a router port yet, it will be added to the router port list with its router port time specified; if
the receiving port is already a router port, its router port time will be directly reset.
When receiving IGMP group-specific-query message, the switch will send the group-specific
query message to the members of the multicast group being queried.
2.
IGMP Report Message
IGMP report message is sent by the host when it applies for joining a multicast group or
responses to the IGMP query message from the router.
When receiving IGMP report message, the switch will send the report message via the router
port in the VLAN as well as analyze the message to get the address of the multicast group the
host applies for joining. The receiving port will be processed: if the receiving port is a new
member port, it will be added to the multicast address table with its member port time specified;
if the receiving port is already a member port, its member port time will be directly reset.
3.
IGMP Leave Message
The host, running IGMPv1, does not send IGMP leave message when leaving a multicast group,
as a result, the switch cannot 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 querier 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 send IGMP leave message to the router and remove
the whole multicast group.

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.
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