How does the Internet really work?
Many technical jobs require an understanding of computer networking. We just posted a great 12-hour course that will give you a deep dive into computer networking.
Here are the sections covered in this comprehensive course:
Course Overview and Procedures
Basic concepts and networking stack
Orientation: Syllabus and Prerequisite (DSA)
Instructor Introduction: Sharthar Sharma
Access to the course (YouTube/Udemy) and target audience
Teaching Method: Crude pen and paper style
Core modules: IPv4, error control, and flow control
Core modules: Transport, Media Access, and Routing
Bonus Module: Cybersecurity
Networking Basics
Definition of computer network
Why networks interact: resource sharing
5 Components of Data Communication
4 Metrics for Network Effectiveness
Transmission Modes: Simplex, Half Duplex, Full Duplex
Connection Types: Point-to-Point vs. Multipoint
Topology and architecture
Introduction to Topology Layout
Mesh topology and link calculations
Advantages and Disadvantages of Topologies
Details of star, bus, and ring topologies
OSI model framework
Layered architecture and peer-to-peer protocols
Binary and IP addressing foundations
Review of Lecture Zero
Binary Number Representation and 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 specification for IP classes
Class A, B, and C disorders
Class Destruction and Classless Requirement (CIDR)
Implementation: Fixing bits for classes AE
IP address space distribution
Hexadecimal and decimal IP representation
Addressing the IPv4 Deep Dive
Class A specification: secure addresses and 127.0.0.1 loopback
Calculating valid hosts and reserved all-zero/all-one
Loopback testing and troubleshooting connectivity
Class B Specifications: Network limitations and host capacity
Class C Specifications: Network/Host Ratio
Class D (Multicasting) and Class E (Experimental)
IP Conversion Practice: Hexadecimal to Decimal
Common Pitfalls: “Leaves” vs. “Valid Hosts”
Subnetting and VLSM
Introduction to Subnetting: Why We Divide Networks
Disadvantages of Subnetting: Waste and Cost
How to Subnet: Borrow Bits from Host ID
Subnet Identification: Calculating subnet IDs and DBAs
Working with weights: Identifying specific subsets
Subnet Mask vs Network Mask
Designing subnet masks for specific needs
Variable length subnet masking (VLSM) strategy
Determining subnet IDs using bitwise AND operations
Routing Tables: Match destination IPs to interfaces
CIDR: Classless Inter-Domain Routing and Slash Notation
Rules for valid CIDR blocks
Supernetting: Merging multiple blocks
Error control and detection
Introduction to Error Control: Noise vs. Security
Single Bit Error vs Burst Error
Redundant bits and block coding logic
Hamming Distance: Calculating the distance between strings
Minimum Hamming distance for detection and correction
Simple Parity: Even vs. Odd Parity Methods
2D Parity: Detecting and Correcting Single-Bit Errors
2D parity bounds for multibit errors
Cyclic Redundancy Check (CRC): Divider and remainder logic
Checksum: One’s Complementary Summarization Method
Flow control and layered architecture
Network Delay: Transmission vs. Propagation
Queuing and processing delays
Data Encapsulation: Headers and Trailers
Need to control the flow: Avoid overwhelming the recipient
Stop and Wait Protocol: Basic Procedures
Using timers and sequence numbers
Calculating performance and round trip time (RTT).
Throughput: The effective bandwidth relationship
Sliding Window Concept: Optimizing Performance
Go-Back-N (GBN) Protocol: Sender/Receiver Windows
Selective Repeat (SR) Protocol: Out-of-Order Handling
Aggregate versus Independent Acknowledgments
Network layer: IP header and routing
IPv4 Header Format Overview
Type of Service (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.
Advertising window (flow control)
TCP control flags: URG, ACK, PSH, RST, SYN, FIN
SYN Flooding Attack (DDoS)
Congestion Control Policy: Slow Start and Avoidance
TCP timers: wait time, keep alive, constant
UDP headers and best-effort delivery
Comparison: TCP vs. UDP
Media access and application support
Multiple Access: Random vs. Controlled Access
Pure Aloha vs. Slotted Aloha Throughput
CSMA (Carrier Sense): Consistent Methods
Polling, Reservation, and Token Passing
Routing: Flooding vs Dynamic Routing
Distance Vector (Bellmanford) vs. Link State (Dijkstra)
Circuit Switching vs. Packet Switching
Email Protocol: SMTP, POP3, IMAP4
Domain Name System (DNS) classification and queries
FTP (File Transfer) and HTTP (Web Services)
Support protocols: ARP and ICMP error reporting
Final Summary: OSI Model Layers 1-7
Check out the full course freeCodeCamp.org YouTube Channel (12 hour clock).