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Cyber Security Tutorial: A Step-by-Step Guide


What is Cybersecurity?

Lesson - 1

Cyber Security for Beginners

Lesson - 2

How to Become a Cybersecurity Engineer?

Lesson - 3

What is Ethical Hacking?

Lesson - 4

What is Penetration Testing?: A Step-by-Step Guide

Lesson - 5

What Is SQL Injection: How to Prevent SQL Injection

Lesson - 6

How to Become an Ethical Hacker?

Lesson - 7

What Is a Firewall and Why Is It Vital?

Lesson - 8

The Complete Know-How on the

Lesson - 9

A Definitive Guide to Learn the SHA 256 Algorithm

Lesson - 10

What Is a Ransomware Attack and How Can You Prevent It?

Lesson - 11

A Look at the Top 5 Programming Languages for Hacking

Lesson - 12

The Most Informative Guide on What Is an IP Address?

Lesson - 13

The Best Ethical Hacking + Cybersecurity Books

Lesson - 14

10 Types of Cyber Attacks You Should Be Aware in 2022

Lesson - 15

The Top Computer Hacks of All Time

Lesson - 16

Top 6 Cyber Security Jobs in 2022

Lesson - 17

The Best Guide to The Top Cybersecurity Interview Questions

Lesson - 18

What Is a Brute Force Attack and How to Protect Our Data Against It?

Lesson - 19

The Top 8 Cybersecurity Skills You Must Have

Lesson - 20

Your Guide to Choose the Best Operating System Between Parrot OS vs. Kali Linux

Lesson - 21

All You Need to Know About Parrot Security OS

Lesson - 22

The Best and Easiest Way to Understand What Is a VPN

Lesson - 23

What Is NMap? A Comprehensive Tutorial for Network Mapping

Lesson - 24

What Is Google Dorking? Your Way to Becoming the Best Google Hacker

Lesson - 25

Your Best Guide to a Successful Cyber Security Career Path

Lesson - 26

The Value of Python in Ethical Hacking and a Password Cracking Tutorial

Lesson - 27

The Best Guide to Understand What Is TCP/IP Model?

Lesson - 28

What Are Keyloggers and Its Effect on Our Devices?

Lesson - 29

Best Guide to Understand the Importance of What Is Subnetting

Lesson - 30

Your Guide to What Is 5G and How It Works

Lesson - 31

How to Crack Passwords and Strengthen Your Credentials Against Brute-Force

Lesson - 32

A Look at ‘What Is Metasploitable’, a Hacker’s Playground Based on Ubuntu Virtual Machines

Lesson - 33

One-Stop Guide to Understanding What Is Distance Vector Routing?

Lesson - 34

Best Walkthrough for Understanding the Networking Commands

Lesson - 35

Best Guide to Understanding the Operation of Stop-and-Wait Protocol

Lesson - 36

The Best Guide to Understanding the Working and Importance of Go-Back-N ARQ Protocol

Lesson - 37

What Are Digital Signatures: A Thorough Guide Into Cryptographic Authentication

Lesson - 38

The Best Spotify Data Analysis Project You Need to Know

Lesson - 39

A One-Stop Solution Guide to Understand Data Structure and Algorithm Complexity

Lesson - 40

Your One-Stop Guide ‘On How Does the Internet Work?’

Lesson - 41

An Introduction to Circuit Switching and Packet Switching

Lesson - 42

One-Stop Guide to Understanding What Is Network Topology?

Lesson - 43

A Deep Dive Into Cross-Site Scripting and Its Significance

Lesson - 44

The Best Walkthrough on What Is DHCP and Its Working

Lesson - 45

A Complete Look at What a Proxy Is, Along With the Working of the Proxy Server

Lesson - 46

A Detailed Guide to Understanding What Identity and Access Management Is

Lesson - 47

The Best Guide to Understanding the Working and Effects of Sliding Window Protocol

Lesson - 48

The Best Guide That You’ll Ever Need to Understand Typescript and Express

Lesson - 49

Express REST API

Lesson - 50

All You Need to Know About Express JS Middleware

Lesson - 51

An Absolute Guide to Know Everything on Expressions in C

Lesson - 52

A Definitive Guide on How to Create a Strong Password

Lesson - 53

Ubuntu vs. Debian: A Look at Beginner Friendly Linux Distribution

Lesson - 54

Your One-Stop Guide to Learn Command Prompt Hacks

Lesson - 55

Best Walkthrough to Understand the Difference Between IPv4 and IPv6

Lesson - 56

What Is Kali NetHunter? A Deep Dive Into the Hackbox for Android

Lesson - 57

A Perfect Guide That Explains the Differences Between a Hub and a Switch

Lesson - 58

The Best Guide to Help You Understand What Is Network Security

Lesson - 59

What Is CIDR? And Its Importance in the Networking Domain

Lesson - 60
What Is CIDR? And Its Importance in the Networking Domain

With the increase in networking devices, either for professional or personal use, they need access to the internet to perform to the best of their capabilities. 

The process of having an IP address assigned and then being routed through the network model to connect to the internet is performed by Classless Inter-domain Routing (CIDR). 

In this article on ‘What Is CIDR?’, we will look into various aspects of the network topic. 

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What Is CIDR?

The CIDR or Classless Inter-Domain Routing is a network concept designed to oversee the assignment of IP addresses to a system to replace the outdated way of a classful addressing system.

This addressing scheme was introduced in the year 1993 by the Internet Engineering Task Force (IETF) to prevent the wastage of IPv4 addresses and to prevent the complexity of routing tables.

Now let’s look into some properties of the CIDR addressing.

Attributes of CIDR Addressing

The addressing of CIDR requires some rules to be assigned:

  1. The IP addresses in a CIDR block are to be continuous, as the ISP will provide them in a sequence of numbers, to minimize the wastage of IP addresses.
  2. The size of the CIDR Block should be of power 2, and to identify the number of addresses assigned, check the subnet mask of the IP address.

Let’s move on to the next part, the working idea of CIDR, in the article ‘What Is CIDR?’.

Working of CIDR

The CIDR uses variable-length subnet masking (VSLM) as the basis of its working, i.e., it acts as a numerical masking sequence that breaks conventional IP addresses into smaller subnets of varying sizes.


Parts of the CIDR IP addresses are mentioned as follows:

Network prefix - This part refers to the binary configuration of the IP network address.

Suffix - This part indicates the number of bits assigned to each CIDR address.

E.g.,, In this IP address,  corresponds to the network prefix.

         /12 refers to the Suffix.

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CIDR Notation

By applying the addressing method discussed in the previous section, ‘Working of CIDR,’ the addressing of an IP address for a host is done without using the standard id classes like Class A, B, and C.


In this CIDR method, we can directly assign and count the number of bits in the network id. For example, in this IP address,, bits after the ‘/’ symbol are used by the Network ID, and the host ID uses the remaining, i.e., (32-10) = 22 bits.

Moving on with the article, let’s look at some disadvantages of applying CIDR.

Disadvantages of CIDR

Applying CIDR addressing provides the network with many advantages, but the disadvantages that arise due to CIDR are as follows:

  1. To minimize the involvement of the routing table in the network, it becomes difficult to determine the route for the network data.
  2. It increases the complexity of the network address, which is one of the benefits of classful addressing.
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In this article on ‘What Is CIDR?’, we looked into some brief explanations about the CIDR, along with information on its properties and working idea, in the network model and its effect on assigning an IP address.

If you want to gain more insights and information about the topic and its various counterparts, you can refer to Simplilearn’s Cyber Security Expert course. After completing this professional course, you will become well versed in working with network security and network-related topics.

If you have any questions about this article on ‘What Is CIDR?’. Feel free to mention them in the comment section at the bottom of this page. Our expert team will help you solve your queries at the earliest.

About the Author

Anmol KapoorAnmol Kapoor

Anmol is a Research Analyst who aims to become a Data Scientist one day. He enjoys Data Management systems and analysis. You will find him reading a book when he is not working.

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