1. What Is an IPv4 Address Class?
The term ‘IP or Internet Protocol’ refers to the Internet layer of Internet protocol suite
that performs the task of exchanging information between addresses of the host and the
destination. Internet Protocol version four or IPv4 is the fourth version in the
development of IP. It is also the first ever version of the protocol that has been widely
installed.
In the beginning, address classes in IPv4 was generally divided into two parts: the
network identifier and the host identifier. When this was not found compatible, another
address was redefined in a way that could surpass the anomalies of the first method.
Thus, the methodology of creating a set of classes of networks, profoundly known as
classful networking came into existence. This method divides the address space for
Internet protocol version 4 into five different address classes, class A, B, C, D, and E.
Each class defines either a network size or multicast networks. Therefore, Class A, B,
and C has different bit lengths for new network identification, Class D is allocated for
multicast addressing and Class E is reserved for future purposes.

2. In the group of IPv4 address class, the first class chosen that is Class A contains all the
addresses in which the most significant bit is 0. The nest seven bits gives the network
number for this class thereby accommodating 128 networks in total including the zero
network and the existing IP network that has been already allocated. Addresses in the
Class B network had the two most important bits 0 and 1. The network address for this
network was given by the next 14 bits of address thereby leaving 16 bits for numbering
host on the network for a total 65536 addresses per network. The third class in the
category of IPv4 address class, i.e., Class C was specified with 3 bits, 1, 1, and 0,
leaving the next 21 bits to networks with 256 local addresses per network. The fourth
category class came with that leading bit sequence, 111 and was left for multicast
addressing. Finally the 1111 block or Class E was left for future experiments.
Although IPv4 network classes, the first architecture system extended the addressing
capability of the Internet, it wasn’t able to prevent the IP address shortage. The problem
was that many sites needed larger address blocks than a Class C network provided. As

3. a result, they received Class B block but this again was much more than needed. Thus,
the unassigned part of Class B network was going in vain.
Later, this system of IPv4 classes was officially replaced with Classless Inter-Domain
Routing (CIDR). This system allowed repartitioning of any address space so that
smaller as well as larger blocks of addresses could be easily allocated to the users.
The fourth version of Internet protocol uses 32-bit addresses now and can be
represented in any notation that expressing a 32 bit integer value. For human
understanding, it is written in dot-decimal notation which contains four octets of the
address expressed individually in decimals and separated by periods. To learn more
about Internet Protocol (IP) and its different version visit http://www.page1hosting.com