RFC 1112:Host Extensions for IP Multicasting
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gateway


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... multicast routers" which may be co-resident with, or separate from, internet gateways. A host transmits an IP multicast datagram ...
... internet host or gateway other than those acting as multicast routers. The algorithms and protocols used within and between ...


... group of all IP hosts (including gateways). This is used to address all multicast ...


... serve other routing-oriented purposes, such as advertising the presence of gateways or resolving local addresses.) ...



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