Addressing : Internet Address and Classful Address

Internet Protocol (IP) Address

An Internet Protocol (IP) address is a number that identifies a device on a computer network. MAC address is a data link layer address that is recognized only in a local so IP address is required for the globally recognized.

Classful address

The classful address is a 32-bit internet address that is used to uniquely identifies the address of the node on the internet. These 32 bits of IP address is divided into network and host portion. There are different five classes i.e. Class A, B, C, D,E.

Class A
•Range : 0 – 127
•So a total of 126 (28-1-2) Networks are possible and total host = 224 in each Network.
•Default subnet mask is 255.0.0.0

Class B
•Range : 128 – 191
•So a total of 216-2 Networks are possible and total host = 216 in each Network.
•Default subnet mask is 255.255.0.0

Class C
•Range : 192 – 223
•So a total of 224-3 Networks are possible and total host = 28 in each Network.
•Default subnet mask is 255.255.255.0

Class D
•Range : 224 – 239
•Used for Multicasting
•E.g. 224.0.0.1 (group)

Class E
•Range 240-255
•Not used ( for future use)

References:

1. A.S. Tanenbaum, “Computer Networks”, 3rd Edition, Prentice Hall India, 1997.
2. W. Stallings, “Data and Computer Communication”, Macmillan Press, 1989.
3. Kurose Ross, “Computer Networking: A top-down approach”, 2nd Edition, Pearson Education
4. Larry L. Peterson, Bruce S. Davie, “Computer Networks: A Systems Approach”, 3rd Edition, Morgan Kaufmann Publishers