IPV 4 and IP Header format

     IPV4 (Internet protocol Version 4)

1. 32 bit dotted decimal value
2. Splitted into 4 octets 
3. Each contains 8 bits
4. Overall 4.3 billion address are available.
5. There are two different areas .

• Network => Network represent area
• Host => Host represent the users in the area 

       1st Octet plays the major role of dividing classes

         128 + 64 + 32 +16 + 8 + 4 + 2 + 1 = 255.

     

      

There are 5 classes:

Class A:  1st Octet 8th bit always 0

A 8 bit Network and 24 bit Host ( 1 octet network 1x8 = 8 and 3 octet host = 8x3 = 24)

Starts at  0.0.0.0 - 127.255.255.255 

0.0.0.0– Not for communication

127.0.0.0 – Loopback Address used by system

User Access Address 1.0.0.0 - 126.255.255.255

Subnet mask - To differentiate host bits and network bits 

                        Host bits are represented as 0 and Network bits are represented as 1

How many users can access Class A network

2^h - 2 = value    (h = number of host bits)

2^24 - 2 = 1,67,77,214  Users can access