RFC 3488:Cisco Systems Router-port G...
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switched network


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... Snooping is a popular, but not well documented mechanism to restrict multicast traffic, in switched networks, to those ports that want to receive the multicast traffic ...


... A router running RGMP on a switched network will not receive traffic for a multicast group ...
... routers forwarding traffic into the switched network need to send RGMP Joins for the group in support ...



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