A Subnet is a directory listing of IP numbers that re used to address on the internet. The number is logical divided so that each part of the number represents a certain function. Usually these subnets contain arrange of IP numbers that are assigned to organizations. So numbers falling into a specific range of subnets can immediately be related to certain organizations. All the numbers allotted to a certain organization will start with the same binary sequence.
In the current day internet scenario the network are increasing and as the networks increase there is more need for network address numbers. However this phenomenon has been creating a limitation in numbers. The only solution to this is to Subnet the addresses. By Subnetting you can keep adding to your network without requiring more IP addresses.
What is IP Addressing
The IP addressing system works by assigning IP numbers to the computers on a network. Every IP address is composed of 32 bits. The first half of the bit is used for identifying a certain network and the second half of the IP number is used to identify the host computer on the network. The first half of the IP address is also called the subnet. These IP addresses are further divided into Class A, Class B and Class C. based on these classes also the IP addresses can be identified.
While Subnetting the IP addresses in a given network some extra measures are taken to make the functionalities of addressing easier. By using a Subnet mask one can determine how many bits can be used for a Subnet and the host computers from the IP address.
A Subnet mask (or number) is used to determine the number of bits used for the Subnet and host portions of the address. The mask is a 32-bit value that uses one-bits for the network and Subnet portions and zero-bits for the host portion.
Here is an example
191 70 55 130
1011 1111 1000 0110 0011 0111 1000 0010 IP address
1111 1111 1111 1111 0000 0000 0000 0000 Subnet mask
1011 1111 1000 0110 0000 0000 0000 0000 Result
There are many advantages of Subnetting in a network. The routing process becomes much simplified by using subnets. Because the routers do not have to fully identify each individual address from a network and route them. It can simply identify a given network using the Subnet address and route. Also the Subnet hides the internal; networks numbers by just giving out the main number to the routers. The routing tables become much shorter by using the Subnet addresses and this means that the data flow also becomes faster.
By using Subnet addresses the entire IP address system becomes centralized. There are many advantages to this feature from technical point of view. The network administrators can assign IP numbers to specific departments in an organization so that when they can easily identify the departments on the network using the same numbers. Also the specific department can now handle all the computers in their own network without depending on the network administrator.
Subnet also divides the bigger network into smaller individual networks and it becomes easy to handle the smaller networks than handle one huge network. Also it removes physical barriers and since the networks now are individually identified all the networks can be connected through routers.
Subnetting is basically subcategorizing the network. Whether it is for one whole company or a few departments within the company, every one can have their own individual way of functioning. When it comes to security, the more easily a network or computer is identified the better it is.