Administrator Guide
Figure 47. 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-specic and general
queries.
1. Host 1 sends a message indicating it is leaving group 224.1.1.1 and that the included lter 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.
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Internet Group Management Protocol (IGMP)