IP Address Classes

To simplify usage, depending on the needs of users,
IP addresses are divided into three classes as shown below
Class Network ID Host ID Default Subnet Mask
A xxx.0.0.1 xxx.255.255.254 255.0.0.0
B xxx.xxx.0.1 xxx.xxx.255.254 255.255.0.0
C xxx.xxx.xxx.1 xxx.xxx.xxx.254 255.255.255.0
IP addresses are given for the class A network with a number of hosts
very large. IP Range 1.xxx.xxx.xxx. - 126.xxx.xxx.xxx, there
16,777,214 (16 million), an IP address in each class A. In the IP address class
A, the network ID is the 8 bit first, while the host ID is 24 bits
next. Thus, how to read the IP address class A,
for example 113.46.5.6 is:
Network ID = 113
Host ID = 46.5.6
IP address numbers above mean 46.5.6 host on the network number 113.
IP addresses are usually allocated to class B-sized networks
medium and large. In class B IP address, network ID is 16 bits
21
First, while the host ID is 16 bits next. Thus,
how to read a class B IP address, for example, 132.92.121.1:
Network ID = 132.92
Host ID = 121.1
IP host address above mean number 121.1 on the network number 132.92.
With a length of 16-bit host ID, network with IP address class B to
accommodate about 65,000 hosts. IP Range 128.0.xxx.xxx -
191.155.xxx.xxx.
Class C IP address originally used for small networks
(LAN). Host ID is 8 bits last. With this configuration, can be formed
about 2 million networks with each network has 256 IP
address. IP Range 192.0.0.xxx - 223.255.255.x.
The allocation of IP address is basically the process of selecting the network ID
and host ID is right for a network. Appropriate or not
This configuration depends on the objectives to be achieved, namely
allocate an IP address as efficiently as possible.