Summary

There are three ways of disseminating information: unicasts, broadcasts, and multicasts. With a unicast, a packet is sent to each destination individually. With a broadcast, a single packet is generated and every destination receives it. With a multicast, a single packet is sent to a group of devices. Class D addresses are used in IP for multicasting: 224.0.0.0–239.255.255.255. These addresses are broken into groups, such as reserved link local, globally scoped, source specific, GLOP, and limited score addresses. 224.0.0.1 is the all-host group and has the IP TTL set to 1. 224.0.0.2 is the all-router group for a segment.

IGMP is used by clients and RPs to determine which clients want to see specific multicast feeds. There are three versions ...

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