How to deal with Ip address and subnet

How to deal with Ip address and subnet

IP Addressing and Subnetting,

In order to understand the concept of IP addressing you must know first what an IP address is. An IP (Internet Protocol) address is a unique 32-bit number assigned to a device which involves in a network.

It is normally expressed in dotted-decimal format, with four numbers separated by periods, such as 192.168.1.1. Sometimes, it is also expressed in binary numbers, and divided into four octets ( 4 groups of 8 bits ). The value in each number (octet) ranges from 0 to 255 decimal or (00000000-11111111 in binary).

There are 5 different classes of IP address, Class A, B, C, D, and E. The most common are only the first three classes. In a Class A address, the first 8 bits or octet refers to the network portion, so a Class A has a network address of 1.0.0.0 – 127.255.255.255.

In a Class B address, the first two octets or 16 bits refers to the network portion, so the Class B has a network address of 128.0.0.0 – 191.255.255.255. The Class C has a network address of 192.0.0.0 – 233.255.255.255 since the first three octets or 24 bits refers to the network portion.

Subnetting is the process of dividing a certain network into subnetwork. It helps us make multiple logical networks that exist within a single Class A, B, or C network. The subnet mask is used in order to determine whether a host is on the local subnet or on a remote network.

There are different reasons why we need to do subnetting. First, we need to divide a large network into small networks in order to reduce traffic.

Another is, to connect networks across different areas. Third is, in order to connect different topologies using routers. Lastly, is to avoid physical limitations like the maximum length of the cable that we have to use or the maximum number of computers that need to be connected.

In subnetting a network, the natural mask is extended using some of the bits from the host ID portion of the address in order to create a subnetwork ID. For example, given a Class C network of 221.045.071.000 which has a mask of 255.255.255.0, you can create subnet in the manner shown below:

11011101.00101101.01000111.00000000 221.045.071.000 Class C IP Address

11111111.11111111.11111111.00000000 255.255.255.000 Class C Subnet Mask

11011101.00101101.01000111.00000000  221.045.071.000 Network Address

In order to get the network address, we must perform a bitwise logical AND operation between the IP address and the subnet mask.

Each class has its own default subnet mask.

For Class A- (decimal)255.0.0.0 or (binary) 11111111.00000000.00000000.00000000

For Class B- (decimal)255.255.0.0 or (binary) 11111111.11111111.00000000.00000000

For Class C- (decimal)255.255.255.0 or (binary) 11111111.11111111.11111111.00000000