Harsh Upparwal
5 min readJan 5, 2021

This guide will ensure that you are familiar with the concepts involved in designing or interacting with networked computers.

Understanding IP addresses
IP Address is a numerical label assigned to each device which simply means it can be accessed by pointing to the destination designation. Your Internet activity passes to them, and they route it back to you, using your IP address.
If one computer wants to connect to another computer, it may be able to retrieve data from the remote computer IP address. Assuming that two computers are in the same network, or that different computers and intermediate devices can translate request across networks, computers should be able to access each other and send data.
Two types of IP addresses are IPv4 and IPv6.

IPv4 vs IPv6
IPv4 uses 32 bits of binary to create one unique address on a network. An IPv4 address is expressed in four dot-separated numbers. Each number is a decimal representation (base 10) of an eight-digit number (base 2), also called an octet.

IPv6 uses 128 pieces of banner to create one unique address on a network. The IPv6 address is expressed in groups of eight hexadecimal numbers (16) separated by colons.

IPv6 space is much larger than IPv4 space due to the use of hexadecimals and having 8 groups. Most devices use IPv4. However, due to the advent of IoT devices and high demand for IP addresses, many devices are adopting IPv6.

Static vs Dynamic
How does your computer get its IP address? IP address can be dynamic or static.
Static address is the one you set by setting your network network settings. This type of address is rare, and can cause network problems if you use it without proper TCP / IP understanding.
Dynamic addresses are the most common. They are provided with Dynamic Host Configuration Protocol (DHCP), a network-based service. DHCP usually works on network hardware such as routers or DHCP dedicated servers. Dynamic IP addresses are issued using the rental system, which means that the IP address is only valid for a limited time. When the agreement is terminated, the computer will automatically request a new agreement.

IP classes
In general, IPv4 space allows us to have addresses between to However, some numbers in that range are reserved for specific purposes in TCP / IP networks. This booking was approved by the official at the TCP / IP address, Internet Assigned Numbers Authority (IANA). Four specific bookings include the following: — This represents the default network, which means to automatically connect to a TCP / IP network. — This address is reserved for network broadcasts, or messages that should go to all computers in the network. — This is called a loopback address, which means your computer identifier, whether or not it has a stolen IP address. to — This is Automatic Private IP Addressing (APIPA) for automated addresses when a computer fails to receive an address from a DHCP server.
Some IP address reservations are for subnet classes. A subnet is a small network of computers connected to a large network by router. A subnet can have its own address system so computers on the same subnet can communicate instantly without sending data to a large network. A router to a TCP / IP network, including the Internet, is configured to receive one or more subnets and network traffic in the correct order.

These are the IP addresses reserved for the subnet: to — This is within the range of Class A address to, where the first bit is 0. to — This is within the range of the Class B to address, where the first two pieces are 10. to — This is within the range of Class C of to, where the first three pieces are 110.
Multicast (formerly known as Class D) — The first four bits of this address are 1110, with addresses ranging from to
Reserved for future use / testing (formerly Class E) — addresses to
The first three (within Classes A, B and C) are the most widely used subnet constructions. Later, we will see how the subnet uses these addresses. The Internet Assigned Number Authority (IANA) has disclosed the direct use of multicast addresses within the Internet Engineering Task Force (IETF) document RFC 5771. However, it has not yet stated the purpose or future plan for the Class E addresses as it has kept the RFC 1112 of 1989. Pv6, the Internet was full of controversy over whether IANA should release class E for normal use.

CIDR notation
A system called Classless Inter-Domain Routing, or CIDR, was developed as an alternative to traditional subnetting. The idea is that you can add a specific IP address to a number of key bits that are part of a route or network.
For example, we would suggest that the IP address is associated with netmask using the CIDR notation of / 24.
This allows us to enjoy other exciting opportunities. We can use them to refer to “supernets”. In this case, we mean the most inclusive address list that is not possible with a traditional subnet mask. For example, in the Class C network, as above, we could not combine addresses from networks and because the netmask for class C addresses is

However, using CIDR notation, we can combine these blocks by identifying this chunk as / 23. This means that there are 23 pieces used for the part of the network we are talking about.

Subnetting process helps to allocate IP addresses that prevent large numbers of IP network addresses from remaining unused. It reduces network congestion, allowing large networks to be divided into smaller networks, each with its own set of IP addresses. This method allows you to apply network security policies at the interconnection between subnets. And Optimizes IP network performance. Subnets are usually set up geographically for specific offices or particular teams within a business that allows their network traffic to stay within the location.

It helps you to maximize IP addressing efficiency. In a way it extends the life of IPV4.

Due to classless addressing the size of routing table increases and to overcome this, the concept of address aggregation is used. It is also called as super-netting here where a router has to send packets, having a group of IP address to only one destination in address aggregation.

Hope this clears your basic networking concepts.