# Subnet Calculator – Basics and Examples

## What is a subnet?

Subnet is also known as subnetwork which in turn is a logical sub – division of the IP network. On the other hand, when a network is divided in to 2 or more than that networks, it is well – known as subnetting. In addition to this, the computers which belong to a certain subnet are usually addressed along with an identical or it can be termed to be a common & the most – significant bit – group in the IP / internet protocol address.

With such a system in place, the result can be seen in the logical division of the IP address that too in 2 fields which are – (1) network or a routing prefix & (2) rest field or the host identifier.  One has to keep the fact in mind that the rest field is nothing short of an identifier for a particular host or for that matter a network interface. Moreover, routing prefix can be expressed in the form of CIDR notation & it is written as the 1st address of a network which is further followed by slash character / before ending with bit – length of the prefix.

$$E.g.\, 192.168.1.0/24$$

The above example happens to be the prefix of the IP or the Internet Protocol Version 4 network. And it starts at the given address besides having 24 bits which are allocated to the network prefix while the rest of the 8 – bits happen to be reserved for the host addressing. On the other hand, IPv6 address specification $$2001:db8:\,:/32$$ turns out to be quite a large address block which has $$2^{96}$$ addresses along with 32 – bit routing prefix.

As far as the IPv4 is concerned then it is characterized by the subnet mask that is stated to be a bitmask which if applied by a bitwise AND operation to the IP address in the network shall yield routing prefix. Apart from this, these subnet masks are expressed in the dot – decimal notation form that too like an address. The best example to explain this has been given below –

$$E.g.\,255.255.255.0\, is\, network\, mask\, for\, 192.168.1.0/24\, prefix$$

### Other points

The traffic is generally routed or exchanged between these subnetworks along with the special gateways / routers. However, this happens only when the routing prefixes of both source & destination address vary.

## What are the benefits of subnetting?

In address allocation architecture of internet using CIDR or the Classless Inter – Domain Routing besides this, in large organisations it becomes necessary to allocate the address space in a proper manner, thus this subnetting comes handy. Routing efficiency is enhanced & there is network management with the assistance of subnetting.

## How is an IP subnet calculator used?

It is quite simple for everyone to make use of this subnet or the subnetwork calculator. However, the most important aspect which cannot be forgotten is that an individual will have to select the network class in order to get the result. You will be also required to click on calculate tab to know the result.