Introduction to Computer Networking
Overview
This document provides original, educational notes covering fundamental computer networking concepts.
It is intended for study, review, and reference purposes.
What Is a Computer Network?
A computer network is a group of interconnected devices that share data, resources, and services. Devices
may include computers, servers, routers, switches, and mobile devices. Networks can be small (home
networks) or extremely large (the internet).
Types of Networks
• LAN (Local Area Network): Covers a small geographic area such as a home, office, or school.
• WAN (Wide Area Network): Spans large geographic areas and connects multiple LANs.
• MAN (Metropolitan Area Network): Covers a city or campus-sized area.
• PAN (Personal Area Network): Very small network, often using Bluetooth.
Network Topologies
• Star: All devices connect to a central switch or hub.
• Bus: All devices share a single communication line.
• Ring: Devices form a closed loop.
• Mesh: Devices are interconnected with multiple paths for redundancy.
Networking Devices
• Router: Connects different networks and routes traffic between them.
• Switch: Connects devices within a LAN and forwards data intelligently.
• Hub: Broadcasts data to all connected devices (largely obsolete).
• Modem: Converts signals for ISP communication.
IP Addressing Basics
An IP address uniquely identifies a device on a network. - IPv4: 32-bit address (example: 192.168.1.1) - IPv6:
128-bit address designed to replace IPv4
Private IPv4 Ranges
• 10.0.0.0 – 10.255.255.255
• 172.16.0.0 – 172.31.255.255
• 192.168.0.0 – 192.168.255.255
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Common Network Protocols
• TCP: Reliable, connection-oriented communication
• UDP: Fast, connectionless communication
• HTTP/HTTPS: Web communication protocols
• FTP: File transfer protocol
• DNS: Resolves domain names to IP addresses
OSI Model (7 Layers)
1. Physical
2. Data Link
3. Network
4. Transport
5. Session
6. Presentation
7. Application
The OSI model helps standardize and troubleshoot network communication.
Basic Troubleshooting Tools
• ping: Tests reachability
• ipconfig / ifconfig: Displays IP configuration
• tracert / traceroute: Shows packet path
Summary
Computer networking enables communication between devices using standardized hardware, addressing,
and protocols. Understanding foundational concepts like IP addressing, network devices, and the OSI
model is essential for further study in IT and cybersecurity.
Original educational content created for study and reference.
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