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version 6 (Ipv6).
Ipv4 was standardized
in 1980s to replace
the
ARPAnet, whereas Ipv6
development started in the 1990s. The details will briefly introduce one by one.
2.4.1 Terminology
Bit -> A binary digit whose value only consists of either 0 of 1.
Byte -> A collection of 8 bits.
Octet -> Always 8 bits.
Prefix length -> Prefix length is the portion of IP address that represents the
network adress. In other words, it's the portion of IP address without the host
address. Further detail will be discussed later on in this chapter.
2.4.2 IPv4
IPv4 is made up of 32 bits of information. They are divided
into
four sections, referred to
as octets.
The IP protocol defines
five different address classes: Class
A, Class
B, Class
C, Class D, and Class
E.
The
first
three classes, Class
A,
B, and C, they
use a different
size
for
the
network ID and and
host ID portion.
Class
D
is
for a special type of address
called multicast and Class E is for experimental only, and is not used.
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