IP Address Class D
IPv4 networking standard defines Class D addresses as
reserved for multicast. Multicast is a mechanism for defining
groups of nodes and sending IP messages to that group rather than to
every node on the LAN (broadcast) or just one other node (unicast).
Multicast is mainly used on research networks. As with Class E,
Class D addresses should not be used by ordinary nodes on the
IP Address Class E
and Limited Broadcast
IPv4 networking standard defines Class E addresses as
reserved, meaning that they should not be used on IP networks.
Some research organizations use Class E addresses for experimental
purposes. However, nodes that try to use these addresses on the
Internet will be unable to communicate properly.
A special type of IP address is the limited broadcast
address 255.255.255.255. A broadcast involves delivering a
message from one sender to many recipients. Senders direct an IP
broadcast to 255.255.255.255 to indicate all other nodes on the
local network (LAN) should pick up that message. This broadcast is
'limited' in that it does not reach every node on the Internet, only
nodes on the LAN.
Technically, IP reserves the entire range of addresses from
255.0.0.0 through 255.255.255.255 for broadcast, and this range
should not be considered part of the normal Class E range.