7 Days Networking Documentation

Mentor:

Gorav Sharma

Day 1: Introduction to Networking

1

Fundamentals of Networking

We began with the very building blocks of networking—understanding how information travels between systems.

Key Concepts

Components of Communication:
  • Sender → the origin of the message (e.g., computer, smartphone)
  • Receiver → the target device receiving the information
  • Transmission Medium → cables (coaxial, fiber optic, twisted pair) or wireless (Wi-Fi, radio)
  • Message → the actual data being transmitted
  • Protocol → the set of rules governing communication (e.g., TCP/IP)
Modes of Communication:

Simplex

One-way communication (TV broadcast)

Half-duplex

Alternating both ways (walkie-talkies)

Full-duplex

Simultaneous both ways (phone calls, video calls)

Analog vs Digital Signals:

Digital dominates due to noise immunity, easier processing, error detection, and higher reliability.

Essential Characteristics of Networking:

Speed, Accuracy, Reliability, Security.

Real-world Link

A WhatsApp message → broken into packets → travels through Wi-Fi/mobile network → passes through routers, ISPs, undersea cables → reassembled on the recipient's device.

Day 2: Types of Network & Nature of Data

2

Network Scaling and Data Flow

We zoomed out to understand network scaling and how data flows.

Types of Networks

LAN (Local Area Network)

Small area (e.g., home Wi-Fi, office)

MAN (Metropolitan Area Network)

City-wide coverage

WAN (Wide Area Network)

Country or global (ISPs, the Internet)

PAN (Personal Area Network)

Very short range (Bluetooth, hotspot)

Network Models

Client-Server Model

Centralized control (Google Drive, Banking)

Peer-to-Peer Model

Equal role devices, sharing directly (BitTorrent)

Performance Factors

  • Bandwidth: Maximum data transfer rate
  • Latency: Time delay in transmission (critical in real-time apps like stock trading)

Nature of Data

  • Oriented (Structured): Databases, spreadsheets
  • Observed: Sensor data from IoT
  • Inferred: Predictions/analytics from AI/ML
Real-world Link

IoT ecosystems mix all network types: Smart homes use PAN/LAN, cities use MAN, cloud connectivity relies on WAN.

Day 3: The OSI Model Demystified

3

7-Layer OSI Stack

We decoded the famous 7-layer OSI stack.

OSI Model Layers

7
Application Layer
User-level communication
HTTP, FTP, SMTP
6
Presentation Layer
Data format conversion
SSL/TLS, compression
5
Session Layer
Manages sessions
RPC, NetBIOS
4
Transport Layer
Reliable delivery
TCP, UDP
3
Network Layer
Logical addressing, routing
IP, ICMP
2
Data Link Layer
Error-free transmission, MAC addresses
Ethernet, ARP
1
Physical Layer
Bits over cables/wireless
Ethernet, Wi-Fi

Encapsulation & De-encapsulation

Data is wrapped with headers & footers at each layer, then unwrapped at the destination.

Hands-on

  • ping → test connectivity
  • traceroute → map a packet's journey hop by hop

Day 4: Inside the Web – HTTP & DNS

4

Web Protocols

We explored the protocols that power the web.

DNS (Domain Name System)

Works like a phonebook: converts example.com → IP address.

nslookup tool → check DNS mappings.

HTTP/HTTPS

Methods:
  • GET → fetch data
  • POST → send data
  • PUT → update data
  • DELETE → remove data

Basis of RESTful APIs.

Response Codes

2xx

Success

3xx

Redirection

4xx

Client errors

5xx

Server errors

Lab Work

Used browser dev tools to monitor requests/responses, caching, and DNS lookups.

Day 5: Revision & DHCP in Action

5

Dynamic Host Configuration Protocol

We revised key concepts and explored DHCP in detail.

Static vs Dynamic IP

  • Static: Fixed IP (servers)
  • Dynamic: Changing IP, assigned by DHCP

DHCP (Dynamic Host Configuration Protocol)

Handshake Process:
# DHCP Transaction Process (DORA)
1. DHCPDISCOVER - Client broadcasts to find available DHCP servers
2. DHCPOFFER - Server responds with an IP address offer
3. DHCPREQUEST - Client requests the offered IP address
4. DHCPACK - Server acknowledges and assigns the IP address lease

Hands-on

Checked a router's DHCP lease table → observed how ISPs assign IPs dynamically.

Day 6: Low-Level Protocols & Diagnostics

6

Protocols and Troubleshooting

We explored low-level protocols and diagnostic tools.

Key Protocols

ARP (Address Resolution Protocol)

IP ↔ MAC mapping in a LAN

ICMP (Internet Control Message Protocol)

Used by ping & traceroute

DHCP Acknowledge

Final confirmation of allocated IP

Hands-on

Used diagnostic tools to trace packets, identify bottlenecks, and debug connections.

Day 7: From Theory to Website Application

7

Practical Implementation

We applied our networking knowledge to a real-world embedded application.

Additional Resources

Further Learning

Expand your knowledge with these recommended cybersecurity and networking resources.

Recommended Books

• "Cybersecurity for Beginners" by Raef Meeuwisse
• "Network Basics for Hackers" by OccupyTheWeb
• "The Web Application Hacker's Handbook"

Online Resources

• Cybrary - Free cybersecurity training
• OWASP Foundation
• Cisco Networking Academy
• Khan Academy Computer Networking

Practice Platforms

• TryHackMe
• Hack The Box
• OverTheWire
• CTFtime.org

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