TP-Link T3700G-28TQ, Руководство пользователя

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IGMPv3 Work Process
Compatible of and Inherited from IGMPv1 and IGMPv2, IGMPv3 further enhances the control
capacity of the hosts and broaden the functions of the query and report messages.
1.
Enhancement of the Hosts
IGMPv3 adds the filtering mode (INCLUDE/EXCLUDE) for the multicast source basing on the
group-specific query. This mode allows the hosts to accept or reject multicast traffic from
specified multicast sources when joining a multicast group.
When a host joins a multicast group:
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If it expects only the multicast data from specified multicast sources, such as S1, S2 … Its
report message can be marked with INCLUDE Sources (S1, S2 …);
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If it doesn’t expect any multicast data from the specified multicast sources, such as S2, S2…
Its report message can be marked with EXLUDE Sources (S1,S2 …);
As shown in Figure 11-4, there are two multicast sources, Source 1(S1) and Source 2(S2),
sending multicast data to multicast group G. Host B is only expecting the multicast data
sending from Source 1 to G.
Figure 11-4 IGMPv3 Multicast Source Filtering
If the IGMP protocol running between the hosts and the multicast routers is IGMPv1 or IGMPv2,
Host B will be unable to select its expecting sources when it joins the multicast group G. Thus
whether needed or not, the multicast data from Source 1 and Source 2 will be transferred to
Host B.
When IGMPv3 is running between the hosts and the multicast routers, Host B will only expect
the multicast data sending from Source 1 to G, referred as (S1, G), or refuse to receive the
multicast data sending from Source 2 to G, referred as (S2, G). Thus only the multicast data
from Source 1 will be transferred to Host B.
2.
Function Enhancement of the Query and Report Message
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