Broadcasts and Multicasts

With Ethernet, broadcasts are specialized frames that are destined for all devices on an Ethernet network. Broadcasts use a MAC address of FF-FF-FF-FF-FF-FF. This is a special MAC address because it is the highest number allowed in the 48-bit schema of MAC addresses. In binary, all 48 bits are set to 1.

Multicasts are specialized broadcasts. Multicasts are used by higher layer protocols to direct traffic to more than one select destination, rather than a broadcast, which is sent to all destinations. Application layer multicasts start with 01-00-5E prefix. The rest of the digits are assigned by the application layer protocol handling the multicast. However, other Layer 2-only multicast addresses do not have the prefix ...

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