There are three classes of IP addresses that can be assigned to
hosts, identifiable by the first octet:
Class A hosts fall within the range of 1-126
Class B hosts fall within the range of 128-191
Class C hosts are between 192-223
The address range from 224.0.0.0 to 239.255.255.255 is known as
Class D and is used for IP multicasting. Class E addresses are
between 240-255, with 255 being used for broadcasting.
A private address range exists within each of the classes and
can be used for hosts that do not directly communicate with the
outside world (other than through an address translator/proxy
server). The ranges, by class, are:
Class A hosts use 10.x.x.x
Class B hosts in the private range are between 172.16.x.x to
172.31.x.x
