Multicast Notes - Part2

Mapping IP Multicast Addresses to MAC Addresses:

01005E(24bits)+binary 0+the last 23 bits of the multicast IP address (48Bits of Mac add), for example :
multicast ip add (228.10.24.5)
01005E+0+
Last 23 Bits =0 0 0 1 0 1 0 . 0 0 0 1 1 0 0 0 . 0 0 0 0 0 1 0 1
                   =   0        A            1          8            0           5


Final mac address = 01-00-5E-0A-18-05

Unfortunately, this method does not provide a unique multicast MAC address for each multicast
IP address, because only the last 23 bits of the IP address are mapped to the MAC address , In fact, because 5 bits from the IP address are always mapped to 0, 25 (32) different class D IP addresses produce exactly the same MAC address.