A. Multicast addresses 224.0.1.0 through 238.255.255.255 are called globally scoped addresses. They are used to multicast data between organizations and across the Internet
B. The multicast address 224.0.0.1 is a globally scoped address that has been reserved for the Network  Time Protocol （NTP） by the IANA
C. Multicast addresses 239.0.0.0 through 239.255.255.255 are called limited scope addresses. They are  constrained to a local group or organization
D. Multicast addresses 224.0.0.5 and 224.0.0.6 are limited scoped addresses that have been reserved for  OSPF
E. Multicast addresses 224.0.0.0 through 224.0.0.255 are used for network protocols on local LAN segments. Because they are always transmitted with a Time to Live （TTL） of 1， they are never forwarded  by a router

A.Multicast addresses 224.0.0.0 through 224.0.0.255 are always forwarded because they are transmitted  with Time to Live （TTL） greater than 1.
B.Multicast addresses 224.0.0.5 and 224.0.0.6 are source multicast addresses for OSPF routers.
C.Multicast addresses 224.0.0.13 and 224.0.0.22 are reserved link-local addresses used by PIMv2 and  IGMPv3.
D.Because they would map to overlapping IP multicast MAC addresses， multicast addresses 224.0.1.1  and 238.1.1.1 could not be used together.
E.Multicast address 224.0.1.1 has been reserved for the Network Time Protocol （NTP） by the IANA
F.The administratively scoped multicast addresses 239.0.0.0 through 239.255.255.255 are similar in  purpose to RFC 1918 private unicast addresses.