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.
The following figure shows the sub-networks of a large single network into 4 smaller sub-networks
- 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
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.
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