Network Concepts and Programming from Scratch - Academic LvL
4.5 (306 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
4,255 students enrolled

Network Concepts and Programming from Scratch - Academic LvL

Networking course with fundamental concepts in depth with TCP/UDP/HTTP Socket Programming for beginners to expert
4.5 (306 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
4,255 students enrolled
Last updated 8/2020
English [Auto]
Current price: $13.99 Original price: $19.99 Discount: 30% off
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This course includes
  • 23 hours on-demand video
  • 2 articles
  • 5 downloadable resources
  • Full lifetime access
  • Access on mobile and TV
  • Assignments
  • Certificate of Completion
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What you'll learn
  • Confident at Answering Networking Related Question
  • Open up opportunities to Networking/System programming Companies
  • Get familiar with Linux and Learn Linux System programming side by side
  • Build Github portfolio, strengthen your employability
  • Decorate your Resume with projects done in this Course
  • Learn Networking concepts at all Layers of OSI Model
  • Course content has been designed keeping the MNCs interviews in Mind
  • Coding Assignments and Projects
  • Become a Networking professional Developer
  • Master designing and Writing TCP/UDP Servers in Linux environment
  • Build & Decode the complete packet from scratch
  • Concept of Packet Encapsulation
  • L2 and L3 Routing, Vlan based Routing
  • Basic UG course on Networking
  • Basic programming skills in C is required

This course is about strengthening the Networking concepts and fundamentals with assignments side by side with theory. Through this course you will be able to :

1. Understand the Functioning of TCP/IP Stack (OSI Model). Understand the function of each layer in TCP/IP stack in good detail.

2. Explain the L2 routing concepts - Mac Addresses and ARP

3Explain the L3 routing concepts - IP Addresses and IP protocol

4. Understand the procedure of Dynamic construction of L3 Routing Table

5. Understand various ways to design a Linux TCP/UDP server program in C

6. Understand Socket programming in C 

7. Understand the Networking devices functioning - L2 switch and L3 router

8. Understand packet Journey through the layers of TCP/IP stack

9. Design and implement HTTP Webservers from scratch

10. Read and manufacture the network packets from scratch

11. Understand the concept of TLVs

12. Concept of packet Encapsulation

13. Understand Domain Name System (DNS)

14. Virtual LANs (VLANs) and Routing in VLANs

15. Broadcast Domain and Collision Domain

We Understand - Networking by its nature is inclined towards being a theoretical subject of study. To arouse the interest of the students ,we elaborate each and every topic of this course through an assignment or project.

This course is thorough. We explain the design, discuss the code flow and then guide the audience how to implement the particular concept design in detail in a step by step manner. All you need is a Linux OS running on your system to do this course.

Who should do this course ?

This course is meant for UG Computer science students, job seekers and professional developers. This is MUST do course for those who want to join MNCs as a developer. The topics covered in this course are of utmost importance from interviews aspects and students graduating in computer science and looking to seek an opportunity in MNCs as a developer should have Networking concepts at his/her finger tips. Better to have done Networking under graduate course, not mandatory. Job seekers trying for the position of Networking developers in product based MNCs System software development including Networking is an evergreen area. Internet will not going to be doomed ever.


There is no pre-requisite for this course, however, it shall be advantage if you know a little of C. We designed this course assuming student is a complete beginner in Networking and we raise the level of course gradually as we move from Basic to advance Networking concepts. 

Also, Please just do not sit and watch my codes. Write your own codes, even if it is same as mine !

We have a strong reasons to choose C as a language for this course:

1. The entire core networking development work is being done in C in industry. So, this reason alone is good enough that you should learn network development in C if you are aiming to join industry as a network protocol developer. 

2. Network equipment need to interact with underlying hardware - the ASIC chips. What could be a better language other than C when it comes to interact and program the hardware.

3. C is middle level language - not as low as assembly, neither as high as Java/Python. In C, its the programmer's responsibility to write every line of code to get the task done, unlike Java/Python which provides rich rest of libraries to do the most tasks for you. Using High Level Languages for learning network programming would obscure the low level details of networking - that is what is going behind the scenes. If you are are beginner in network programming, you must learn things from scratch and only C provides you the opportunity to do that. So, you must do all your assignments in C.

4. Networking is all about cooking up the packets and sending it out of wire. C will allow you to cook packets exactly the same way as you would like them to appear on wire. Lot of Bit level programming.  

5. If you are a beginner in Networking, pls refrain from learning network programming in High Level Languages such as Java Or Python. It is not job oriented thing to do in networking domain.

No Third Party libraries

Whatever logic you implement, you need to implement it from scratch. This course do not suggest taking help of any third party library to get the jobs done. Use of external libraries completely defeats the purpose of the course. However, it is recommended to use third party libraries for commonly used data structures such as linked lists/Trees/Queues etc which saves a lot of time implementing these data structures.

What else along with the course ?

If you are aiming to become a developer, then, besides strong in Data structure and Algorithms, you should have clarity of concepts related to other Linux utilities. Networking is all about system programming, and you would be interested in learning other linux concepts of prime importance such as Inter Process Communication, Remote Procedure Calls etc. Please take a look at my other courses in this regard. These courses will summed you up as a more competitive developer in Networking & System Programming domain.

See what students are saying about this course

Just Take a Look at These Top Rated Reviews (Browse review section to verify these reviews)

***** What a Fantastic Course!!! I really appreciate the efforts Abhishek has put in this course. He has put his sweat and heart into it. The way he explains things keeps you hooked on to this course. He directly gets TO THE POINT without beating around the bush. No author of any networking book can explain things like Abhishek is doing. What Abhishek is doing is that he is explaining the Meat of the subject. One would have to read 10 books to understand this. or perhaps more. There was a hunch in my heart that dont know networking clearly. This course meets my expectations with respect to content, clarity and teaching style with proper presentations. This course improves your understanding and removes the fear of not knowing...not only that, it injects a good amount of confidence about your knowledge of Networking...Thanks for coming up with such a course. Thanks Again.

***** Come across right course at right time. This course seems cover all important areas of networking. Author explains the topics in good detail and with good pace. This course looks like designed to beat technical interviews.

***** Great Course, instructor is very thorough and provide quick guidance and clear any doubts promptly with high availability. I really enjoyed this course. Networking has been a tough subject for me to learn, but this course has made it quite easy. I now have my concepts thoroughly clear ! Thanks Abhishek, and Udemy.

***** I am working as Firmware/Embedded engineer, and the courses from this guys are goddamn blessing. In the real industry, as he mentioned earlier, all network programming or Linux system programming must be implemented with C cuz C is a perfect language for accessing memory spaces and customizing serial communication with other chips. In the real industrial fields, no one is gonna teach you. You are the only one who needs to figure it out by yourself cuz everyone wishes you not to excel in workplace. Only one person can be a manager or supervisor. Take this guy's courses. Needless to say, quality guaranteed. If I could do hacking on this site, i am gonna crash his lectures. I do not want other people to get benefits from his lectures. It would be best if he makes a lecture for "making Operating System from scratch" :) 

Warning : This course has auto system-generated subtitles which may not be perfect. Please disable subtitles as per your convenience.


0. Setting up Linux Development Environment on your machine 

  • For those who are not familiar with Linux Installation/environment

1. OSI Model Vs TCP/IP Stack

  • Data Encapsulation and Data Decapsulation

  • Headers Cascading

  • Ingress and egress Journey of packet through a TCP/IP Stack

  • Big Picture

2. Multi-node setup environment on your machine

  • Setup Multinode Cluster of Virtual machines on your machine

  • Local and Remote Subnets

  • Layer 3 Route Semantics

  • Configure Layer 3 routes in nodes

  • Understand L3 Routing table semantics 

3. Subnetting and IP address

  • Understand Subnets

  • Differentiate between local and remote subnets

  • IP Address assignment scheme/policy

  • Data Delivery

  • Understand MAC addresses and their use

  • Calculation of Networking ID, Broadcast address and Cardinality of a subnet

  • Understand the relationship between L3 routers and Subnets

  • Understand Point-to-Point links

  • MAC layer and IP rules of packet rejection/acceptance

  • Broadcast Addresses

4. Layer 2 Networking concepts

  • L3 Router as a gateway to subnet

  • Protocol Identifier fields at each layer

  • Ethernet header format

  • How Ethernet hdr makes L2 routing possible

  • ARP (Address resolution protocol)

  • ARP table population and use

  • Step by Step ARP protocol functioning

  • Assignment on ARP

  • Layer2 Switch - How it works 

  • MAC address table

  • Step by Step description of L2 Switch functioning

  • Problem of Layer Thrashing

5. Layer 3 Networking concepts

  • Relationship between Layer2 and Layer3 routing

  • Explained the dependency of two layers over each other

  • Configuring Layer 3 routing table

  • Semantics of a Layer 3 route

  • Layer 3 route look up

  • Concept of Longest prefix match

  • IP Header - fields you should know

  • Network Layer Operations

  • Step by Step description of L3 routing routing

  • Loopback interface - purpose and configuring loopback interface 

  • Exercise on Layer 3 route installation, routing and forwarding of traffic

  • BroadCast and Collision Domain

6. Dynamic Construction of L3 Routing Table

  • Phase 1 - Neighbotship database management

  • Phase 2 - Creation of Link State Database

  • Phase 3 - Shortest Path first Algorithm

  • Calculation of Final Routing Table

7. Virtual LANs (VLANs)

  • LANs and why they are outdated today

  • VLANs - The purpose

  • 802.1Q VLAN hdr

  • Rules of Vlan Tagging

  • Vlan Aware L2 Switches

  • Vlan based L2 routing

  • Other Vlan Benefits

8. Router to Vlan Forwarding

  • Convept of SVI interfaces

  • SVI - VLAN Binding

  • Router to Vlan Forwarding - Step by Step

9. Inter Vlan Routing

  • Two Step Process

    • From Src host Machine to Gateway L3 router

    • From Gateway L3 router to Dst host machine

    • Exercise and more examples

10. Network troubleshooting tools

  • How ping works - ICMP protocol description

  • Networking applications troubleshooting utilities - ping, wireshark, tcpdump 

  • Capturing the packets and examine its contents using tcpdump

11. Transport Layer

  • Layer Goals

  • Contrasting Layer2, Layer 3 and Layer 4 together

  • TCP and UDP - Properties of two protocols

  • TCP Vs UDP

  • Understanding TCP in Detail

  • Concept of Headers stacking

  • Concept of port numbers

  • Linux System call interface

12. Socket programming concepts

  • Socket Programming Design

  • Select System call

  • Accept System call

  • Concept of Multiplexing

  • Server State machine

13. Application Layer 

  • Different ways to implement Sockets

    • on Top of Transport layer

    • on Top of Network Layer

    • on Top of  Data link layer

  • Designing HTTP Webserver from scratch

  • HTTP Webserver Implementation

  • Custom application sockets

14. Domain Name System

  • What is DNS ?

  • DNS Architecture and Design

  • FQDN

  • Hosting a website

  • DNS Resolver

  • DNS Query types

    • Iterative Query

    • Recursive DNS Query

    • Reverse DNS Query

  • Summary

15. IP-in-IP Encapsulation/Tunneling

  • What is IP-in-IP Encapsulation ?

  • Why we need IP-in-IP Encapsulation ?

  • How Encapsulated packet is routed in the network ?

  • Two scenarios using IP-in-IP Encapsulation

16. Concept of TLVs

  • What are TLVs

  • Why we need TLVs

  • Writing a TLV decoder

  • Benefits of TLVs in Network communication

  • STREAMS - Data Structure

  • TLV (De)Serialization using STREAMS


2 Aug 2020 - Added Section on Dynamic Construction of L3 Routing Table

14 June 2019 - Added Section on TCP

06 Oct 2018 - Added Section 6 On VLANs

07 Sept 2018 - Added Section 11, Domain Name System

13 July 2018 - Added Section 12, IP-in-IP Encapsulation/Tunneling

17 June 2018 - Added Section 10, The Application Layer and HTTP Webserver Design & Implementation

10 June 2018 - Added Section 15, The concept of TLVs

Who this course is for:
  • UG students, PG Students
  • Those looking to build a career in Networking Domain
  • Coding lovers who love to build projects and see things in Action
  • Those, who want to distinguish themselves from Crowd
Course content
Expand all 191 lectures 23:06:26
+ Introduction
11 lectures 01:11:09
Join Us

This lecture is for those, who have never worked with Linux and are not familiar with it all. Also, those who are not familiar wrt to how to setup linux OS running on top of virtualization software will find this lecture useful. Please excuse with the low sound volume of this lecture.

Setting Up Linux Development Environment

Get an overall idea of OSI MODEL and learn the relationship between OSI model and TCP/IP Stack

Preview 12:58
OSI Model Layers Functions
TCP IP Stack real World Analogy
Data Encapsulation and Decapsulation - Introduction
Data Encapsulation
Data Decapsulation
A Big Picture

Answer the Questions as per the instructions in the question itself.

Test your Understanding
2 questions
+ MultiNode Topology
3 lectures 44:38
Local And Remote Subnets
L3 Routing Information
L3 Routes
+ Networking Labs
6 lectures 31:47
What in this Section ?
Objective and Goals
Mininet Installation Procedure
Extra Tools Installation
Launching Mininet
Mininet TreeTopologies
+ IP Subnet
11 lectures 01:42:24
Subnetting Part 1
Subnetting Part 2
Data Delivery
Mac and IP Address
Network ID
Broadcast Addresses
Max Value and Control Bits
IP Address Configuration
Point to Point Links Mask
Broadcast Addresses In Detail

Coding assignments to be done in C/C++. See the Resource section. Solution is present in file solution.c. Second solution is also given by one of the Student (Credit : Fadhel). Read the solution.c file header to compile and run the solution.

Preview 11:58
+ Layer 2 Routing
16 lectures 02:09:35
L2 Routing Introduction
L2 Routing - Basics
Ethernet Header format
How Layer 2 Routing is done ?
ARP Goals
ARP Standard Message Format
Address Resolution Protocol Part 1
Address Resolution Protocol part 2

Warning : Audio Quality is not good for this Lecture Video !

Address Resolution Protocol Demonstration
Layer 2 Switch Concept
L2 Switch Functioning
Layer 2 Switch Example
Pls answer the questions as per the instructions stated in Question itself.
1 question
Lab Session
Test Topology Description
L2 Topology Demo
L2 Topology Assignment
+ Layer 3 Routing
12 lectures 02:01:25
Layer 3 Routing Overview
Why we need L3 Routes ?
Semantics of Layer 3 Routes
Routing table Look up
L3 Routing Topology
Layer 3 Operations and Flowchart
Layer 3 Routing Example
Loopback interfaces - Introduction
Loopback interfaces - properties
Routing using Loopback IP Address as Destination Address
Lab Session on L3 Routing
L3 Topology Construction and Demo
Answer as per the instruction described in the Question
Check your Understanding
2 questions
+ Dynamic Construction of Layer 3 Routing Table
6 lectures 29:45
Goals and Problem Statement
Routing Table Entry Format
ECMP - Equal Cost Multiple Path
L3 Device Collaboration
Generic Steps to Build Routing Table
+ Part2 - Dynamic Construction of Layer 3 Routing Table
10 lectures 54:17
Phases of This Section
Phase 1 - 4 Steps
Phase 1 - Step 1 and 2
Phase 1 - Steps 3 and 4
Phase 2 - Spf Algorithm
Phase 2 - Spf Algo Example 1
Phase 2 - Spf Algo Rules
Phase 2 - Spf Algo Example 2
Phase 3 - Final Routing Table Computation
+ Broadcast Domain and Collision Domain
3 lectures 16:19
BD and CD - Introduction
Collision Domain reduction by L2 Switches - Example1
Broadcast Domain reduction by L3 router - Example2
+ LANs and VLANs
16 lectures 01:22:09

Let us Understand LANs what are their Use Cases

What are LANs and Use Cases
LANs Problem 1 - Immobility
LANs Problem 1 - Immobility Real World Example
LANs Problem 2 - Security Issues
Introducing VLANs
Access and Trunk Ports of L2 Switch
802.1Q VLAN Header
VLAN Tagging Rules
VLAN L2 Routing Example - Part1
VLAN L2 Routing Example - Part2
VLAN L2 Routing Example - Part3
Pls follow the instructions as given in Question.
1 question
VLAN Benefit 1 - Segmentation
VLAN Benefit 2 - Resolve Thrashing
VLAN Benefit 3 - Reduced Broadcast Domain
VLAN Benefit 4 - Mobility
VLANs Additional Reading