# IP address Classes | IP Address Classes With Network Id And Host Id Class A,B,C,D

IP address is 32 bit number.
32 bit number has two portion network portion & host portion. 32 bits number are divided into four octets so each octets has 8bits.Binary digit can converted into decimal and they are represented into dotted decimal format. The value of each octet can vary from 0 to 255.
Class A:Class A IP address structure.
NNNNNNNN: HHHHHHHH: HHHHHHHH: HHHHHHHH
N-network
H-Host

Ex IP : 10.0.0.1
Value of the first bytes: 1 to 126
No of the network: 126No of the Host: (256*256*256)-2=16,777,216-2=16,777,214
Because two hosts we are not using so we reduce 2.
X.0.0.0 and
x.255.255.255
Purpose: we can use class A with large network with many devices because it contains too many host on the same network 16,777,214-host.

Class B: Class B IP address structure.NNNNNNNN: NNNNNNNN: HHHHHHHH: HHHHHHHH
N-network
H-Host

Ex IP: 130.10.0.1
Value of the first bytes: 128-191
No of the network: (191-127)*256=16,384
No of the Host: (256*256)-2=65,536-2=65,534
Because two hosts we are not using so we reduce 2.
X.X.0.0 and
x.x.255.255
Purpose: we can use class B with Medium network with many devices because it contains host on the same network 65,534-host.

Class C: Class C IP address structure.
NNNNNNNN: NNNNNNNN: NNNNNNNN: HHHHHHHHN-network
H-Host

Ex IP: 192.168.5.1
Value of the first bytes: 223-192
No of the network: (223-191)*256*256=2,097,152
No of the Host: (256)-2=254
Because two hosts we are not using so we reduce 2.
X.X.0.0 and
x.x.255.255
Purpose: we can use class c with small network because it contains very low no of host on the same network 254-host.

Class D:
Range:224-239
Purpose: it is used for multicasting
Class E:Range: 240-254
Purpose: now it is not using .Reserved for Future use.