Subnetting and Its Types
- Subnetting is a process in which a single network is divided into multiple sub-networks.
- The sub-networks are also called subnets.
Example
The following figure shows the sub-networks of a large single network into 4 smaller sub-networks
Subnet ID
- Each sub-network has its unique network ID known as its Subnet ID.
- The subnet ID is created by borrowing some bits from the part of the Host ID.
- The number of bits borrowed from hosts depends on the number of subnets created.
Types of Subnetting
Subnetting of a network can be achieved through the following methods
1. Fixed Length Subnetting
Fixed-length subnetting is also called classful subnetting. Fixed-length subnetting holds the following properties.
- The sizes of all sub-networks are the same.
- Subnets of all subnetworks are the same.
- All the sub-networks have an equal number of hosts.
2. Variable Length Subnetting
Variable length subnetting is also called classless subnetting. Variable length subnetting holds the following properties.
- The sizes of all sub-networks are not the same.
- Subnets of all subnetworks are not the same.
- None of the sub-networks have an equal number of hosts.
Advantages of Subnetting
Subnetting improves security because the administration and maintenance of sub-networks is easy.
In simple words, the management and maintenance of the entire university is tough as compared to its different departments.
Disadvantages of Subnetting
Point-01:
Subnetting leads to the loss of IP Addresses. Two IP Addresses are always wasted for every sub-network (subnet).In subnetting, One IP Address is wasted for its network address and another for its direct broadcasting address.
Point-02:
Subnetting leads to a more complicated communication process than communication without subnetting.
After subnetting, the communication is done through the following 4 steps
- First, Identifying the network
- Second, Identifying the sub-network
- Third, Identifying the host
- And in the last, Identifying the process