Multicast Listener Reports; Multicast Listener Done Messages; Platform Considerations; Chapter 6 Configuring Multicast Listener Discovery - Juniper JUNOSE 11.0.X MULTICAST ROUTING Configuration Manual

The purpose of a membership group query is to discover the multicast groups to
which a host belongs.
MLDv1 and MLDv2 multicast listener queries have a Max Response Time field. This
response time is the maximum that a host can take to reply to a query.

Multicast Listener Reports

When a host receives a multicast listener query, it identifies the groups associated
with the query and determines to which groups it belongs. The host then sets a timer,
with a value less than the Max Response Time field in the query, for each group to
which it belongs.
When the timer expires, the host sends a multicast listener report to the group
address. When a multicast router receives a report, it adds the group to the
membership list for the network and sets a timer to the multicast address listening
interval. If this timer expires before the router receives another multicast listener
report, the router determines that the group has no members left on the network.
If the router does not receive any reports for a specific multicast group within the
maximum response time, it determines that the group has no members on the network.
The router does not forward subsequent multicasts for that group to the network.
MLDv2 supports an extended report format that allows you to report multiple groups
and source lists in a single report. These reports are addressed to the all-MLDv2
router's multicast address (FF02::16).

Multicast Listener Done Messages

When an MLDv1 host leaves a group, it sends a multicast listener done message to
multicast routers on the network. A host generally addresses multicast listener done
messages to the all-routers address, FF02::2.
When an MLDv2 host leaves a group, it sends a multicast listener report. This report
includes an empty source list for that group.

Platform Considerations

For information about modules that support MLD on the ERX7xx models, ERX14xx
models, and the ERX310 Broadband Services Router:
Group-specific queries
Source-specific queries
See ERX Module Guide, Table 1, Module Combinations for detailed module
specifications.
See ERX Module Guide, Appendix A, Module Protocol Support for information about
the modules that support MLD.
Chapter 6: Configuring Multicast Listener Discovery

Platform Considerations

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