​Computer Networking Fundamentals

How does the Internet really work? For many technical jobs it is important to understand computer networking. We just posted a massive 12-hour course that will give you a deep dive into computer networking. Here are the sections covered in this compr… 

How does the Internet really work?

For many technical jobs it is important to understand computer networking. We just posted a massive 12-hour course that will give you a deep dive into computer networking.

Here are the sections covered in this comprehensive course:

Course Overview & Methodology

  • Fundamental Concepts and Networking Stack

  • Orientation: Curriculum and Prerequisite (DSA)

  • Introduction to the Instructor: Shrathir Sharma

  • Course Access (YouTube/Udemy) and Target Audience

  • Teaching Methodology: Raw Pen & Paper Style

  • Core Modules: IPv4, Error Control, and Flow Control

  • Core Modules: Transport, Media Access, and Routing

  • Bonus Module: Cybersecurity

Networking Basics

  • Defining a Computer Network

  • Why Networks Interact: Resource Sharing

  • 5 Components of Data Communication

  • 4 Metrics for Network Effectiveness

  • Transmission Modes: Simplex, Half-Duplex, Full-Duplex

  • Types of Connections: Point-to-Point vs. Multi-Point

Topology & Architecture

  • Introduction to Topology Layouts

  • Mesh Topology and Link Calculations

  • Advantages and Disadvantages of Topologies

  • Star, Bus, and Ring Topology Details

  • The OSI Model Framework

  • Layered Architecture and Peer-to-Peer Protocols

Binary & IP Addressing Foundations

  • Review of Lecture Zero

  • Binary Number Representation & Conversion

  • Binary Weights and Octet Conversions

  • Introduction to IPv4 Logical Addressing

  • Network ID vs. Host ID and IANA Authority

Classful vs. Classless Addressing

  • Telephone Network Analogy for IP Classes

  • Class A, B, and C Breakdown

  • Classful Wastage and the Need for Classless (CIDR)

  • Implementation: Fixing Bits for Classes A-E

  • IP Address Space Distribution

  • Hexadecimal and Decimal IP Representations

IPv4 Addressing Deep Dive

  • Class A Details: Reserved Addresses & 127.0.0.1 Loopback

  • Calculating Valid Hosts and Reserved All-Zeros/All-Ones

  • Loopback Testing & Troubleshooting Connectivity

  • Class B Details: Network Ranges & Host Capacity

  • Class C Details: Network/Host Ratios

  • Class D (Multicasting) and Class E (Experimental)

  • IP Conversion Practice: Hexadecimal to Decimal

  • Common Pitfalls: “Addresses” vs. “Valid Hosts”

Subnetting & VLSM

  • Introduction to Subnetting: Why We Divide Networks

  • Disadvantages of Subnetting: Wastage and Cost

  • How to Subnet: Borrowing Bits from Host ID

  • Subnet Identification: Calculating Subnet IDs and DBAs

  • Working with Weights: Identifying Specific Subnets

  • Subnet Masks vs. Network Masks

  • Designing a Subnet Mask for Specific Requirements

  • Variable Length Subnet Masking (VLSM) Strategy

  • Determining Subnet IDs using Bitwise AND Operations

  • Routing Tables: Matching Destination IPs to Interfaces

  • CIDR: Classless Inter-Domain Routing & Slash Notation

  • Rules for Valid CIDR Blocks

  • Supernetting: Merging Multiple Blocks

Error Control & Detection

  • Introduction to Error Control: Noise vs. Security

  • Single Bit Error vs. Burst Errors

  • Redundant Bits and Block Coding Logic

  • Hamming Distance: Calculating Difference Between Strings

  • Minimum Hamming Distance for Detection and Correction

  • Simple Parity: Even vs. Odd Parity Methods

  • 2D Parity: Detecting and Correcting Single Bit Errors

  • Limitations of 2D Parity for Multi-Bit Errors

  • Cyclic Redundancy Check (CRC): Divisor & Remainder Logic

  • Checksum: One’s Complement Summation Method

Flow Control & Layered Architecture

  • Network Delays: Transmission vs. Propagation

  • Queuing and Processing Delays

  • Data Encapsulation: Headers and Trailers

  • The Need for Flow Control: Avoiding Receiver Overwhelm

  • Stop and Wait Protocol: Core Mechanism

  • Using Timers and Sequence Numbers

  • Calculating Efficiency and Round Trip Time (RTT)

  • Throughput: Effective Bandwidth Relationship

  • Sliding Window Concept: Improving Efficiency

  • Go-Back-N (GBN) Protocol: Sender/Receiver Windows

  • Selective Repeat (SR) Protocol: Out-of-Order Handling

  • Cumulative vs. Independent Acknowledgments

Network Layer: IP Header & Routing

  • IPv4 Header Format Overview

  • Type of Services (TOS): Priority and DTRC Bits

  • Time to Live (TTL): Preventing Infinite Loops

  • Protocol Field and Header Checksum

  • IP Options: Strict vs. Loose Source Routing

  • TCP Header Structure: Ports, Sequence, and Ack

  • Wrap Around Time and Segment Lifetime

  • Advertisement Window (Flow Control)

  • TCP Control Flags: URG, ACK, PSH, RST, SYN, FIN

  • SYN Flooding Attack (DDoS)

  • Congestion Control Policy: Slow Start & Avoidance

  • TCP Timers: Time-Wait, Keep-Alive, Persistent

  • UDP Header and Best-Effort Delivery

  • Comparison: TCP vs. UDP

Media Access & Application Support

  • Multiple Access: Random vs. Controlled Access

  • Pure Aloha vs. Slotted Aloha Throughput

  • CSMA (Carrier Sense): Persistent Methods

  • Polling, Reservation, and Token Passing

  • Routing: Flooding vs. Dynamic Routing

  • Distance Vector (Bellman-Ford) vs. Link State (Dijkstra)

  • Circuit Switching vs. Packet Switching

  • Email Protocols: SMTP, POP3, IMAP4

  • Domain Name System (DNS) Hierarchy & Queries

  • FTP (File Transfer) and HTTP (Web Services)

  • Support Protocols: ARP and ICMP Error Reporting

  • Final Summary: OSI Model Layers 1-7

Watch the full course on the freeCodeCamp.org YouTube channel (12-hour watch).