Dell S4048-ON, Configuration Manual

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3. The host’s third message indicates that it is only interested in traffic from sources 10.11.1.1 and 10.11.1.2. Because this request
again prevents all other sources from reaching the subnet, the router sends another group-and-source query so that it can
satisfy all other hosts. There are no other interested hosts so the request is recorded.
Figure 50. Membership Reports: Joining and Filtering
Leaving and Staying in Groups
The following illustration shows how multicast routers track and refresh state changes in response to group-and-specific and general
queries.
1. Host 1 sends a message indicating it is leaving group 224.1.1.1 and that the included filter for 10.11.1.1 and 10.11.1.2 are no longer
necessary.
2. The querier, before making any state changes, sends a group-and-source query to see if any other host is interested in these
two sources; queries for state-changes are retransmitted multiple times. If any are, they respond with their current state
information and the querier refreshes the relevant state information.
3. Separately in the following illustration, the querier sends a general query to 224.0.0.1.
4. Host 2 responds to the periodic general query so the querier refreshes the state information for that group.
Internet Group Management Protocol (IGMP)
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