IP address classification

IP addresses are classified into 5 classes

• class A
• class B
• class C
• class D
• class E

class a,b,c are used in LAN,WAN

class D is reserved for multi casting.

class E reserved for research and development. 

ip address are classified based on priority bits. you can learn about the priority bits in class explanations.

CLASS A:

range:

0 0 0 0  to 127 255 255 255

   0  X  X  X  and  127  X  X  X  are reserved.

see here if we write this bits in binary form it will be

      00000000 00000000 00000000 00000000       to

              (0)         (0)              (0)           (0)

      01111111 00000000 00000000 00000000

          (127)         (0)               (0)         (0)

the first 8 bits are first octet second 8 are second octet.

from the first octet

0 0 0 0 0 0 0 0 = 0

0 0 0 0 0 0 0 1 = 1

0 0 0 0 0 0 1 0 = 2

0 0 0 0 0 0 1 1 = 3

.

.

.

.

0 1 1 1 1 1 1 1 = 127

if you observed this you can understand that the first most bits of this octet(first octet of class A ip address)

are "0".

     so the priority bit of class A ip address is "0".

and each and every ip address are divided into network and host portion.

in class A ip address the formation of network and host portion is N.H.H.H 

       N.                 H.              H                 H

(00000000   00000000   00000000    00000000

FOR EXAMPLE 

   10.0.0.13 is belongs to class a ip address
 in this ,

10- NETWORK PORTION 

0.0.13-HOST PORTIONS

N.H.H.H

10.0.0.13

it means 10. is a network and the 0.0.13 is a host in the 10. network

network bits: 8  and host bits: 24

how many no of networks in class A:

2^{no of network bits-priority bits}     

=2^8-1      

=2⁷      =  128

128-2=126   ("-2" is for, in class A 0 and 127 networks are reserved as prescribed)

2^{number of network bits}-2
= 2²⁴ - 2
 = 16777216 - 2  (-2 is for, in every network the first host and lost host is for network ID & broadcast ID)
 = 16777214 hosts / network.

it means for every class A ip address network we can use 16777214 ip addresses (it means we can use 16777214 computers in each network of class A).

network ID : in each network the ip address with all zeros in host portion (the first ip address of network) is the network ID.
broadcast ID: the ip address with all one's in host portion (the last ip address of a network) is the broadcast ID.


ex:   10.0.0.0----------> is the network address
       10.0.0.1
        .
        .
        .
        .
        .
      10.255.255.255----------> broadcast address.

CLASS B:

similarly

range 128 0 0 0   to  191 255 255 255

priority bits : 2 (10)

in class A ip address the formation of network and host portion is N.N.H.H 

ex: 176.16.12.13

network bits 16   host bits  : 16

no of networks : 16384 networks

no of hosts : 65534 hosts / network.

example fro network address: 172. 16. 0. 0
example for broadcast address: 172.255.255.255

CLASS C:

similarly

range 192 0 0 0   to  223 255 255 255

priority bits : 3 (110)

in class A ip address the formation of network and host portion is N.N.N.H 

ex: 192.168.1.13

network bits : 24   host bits  : 18

no of networks : 2097152 networks

no of hosts : 254 hosts / network.

example fro network address: 192. 168. 0. 0
example for broadcast address: 192.168.1.255.

CLASS D:

range: 224 0 0 0   to 239 255 255 255

CLASS E:

range: 240 0 0 0    to  255 255 255 255

  if you are  not aware of binary forms please learn those.

 A VIDEO TUTORIAL FOR IP ADDRESS CLASSES AND BINARY DECIMAL CONVERSION

THANK YOU.....!   I HOPE YOU UNDERSTOOD...