Dell S4048–ON Configuration Manual page 373

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-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) 373