(Revised 2013-06-21)
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Step2: Map those 23 bits into the low order 23 bits of a MAC address with the fixed high order 25 bits of the
IEEE multicast addressing space prefixed by 01:00:5E.
An example of this process is shown below. This example assumes that the application has selected the IP
class D address 239.1.1.10 and demonstrates the mapping of the low order 23 bits of the class D IP address
to the low order bits of the MAC layer destination.
Mapping of class D 226.129.1.10 IP address to MAC layer multicast
The mapping of 226.129.1.10 to a MAC layer multicast was executed by placing the low order 23 bits of the
class D address into the low order 23 bits of the reserved MAC layer multicast address 01:00:5E:xx:xx:xx.
Since only 23 bits are mapped, the 24th significant bit is fixed at 0. The final MAC address that is utilized by
the multicast group 226.129.1.10 is 01:00:5E:01:01:0A.
