Computer Applications Technology - Grade 11

Local Area Networks (LAN)

• Definition: A LAN is a network that covers a small geographical area, typically confined to a single building or group of buildings.

Types of Networks

• Personal Area Network (PAN): Organized around an individual, generally within a range of a few meters (Bluetooth devices).
• Home Area Network (HAN): Network in a home setting, connecting various personal devices.
• Local Area Network (LAN): Small area, generally within one building.
• Internet: Global network that connects millions of private, public, academic, business, and government networks.
• Intranet: A private network within an organization, using internet technologies and protocols.

Basic Components of a Network

• Hardware: Includes devices such as computers, servers, switches, and printers.
  • Computers and Peripherals: Client devices like desktops, laptops, tablets, and smartphones.
  • Servers:
  • File server
  • Email server
  • Proxy server
  • Web server
  • Print server
  • Database server

Connection Indicators

• Indicators of Network Connectivity:
  • Presence of extra logical drives (e.g., U:, V:, T:)
  • Visibility of other computers in the network
  • Access to shared devices such as printers
  • Network activity indicators in notification area.

Network Interface Controller (NIC)

• Purpose: Connects devices to the network.
  • Can be a wired connection (using UTP or fibre optic cables) or wireless using Wi-Fi adapters.

Communication Methods

• Cables:
  • Unshielded Twisted Pair (UTP): Common for LAN connections but has limitations such as distance and susceptibility to interference.
  • Fibre Optic Cable: Supports longer distances and immune to electromagnetic interference, offering faster data transmission.
• Wireless Communication:
  • Wireless Access Points allow for mobility and connection of devices without cables.

Advantages of LAN

• Centralized file storage.
• Shared internet connection.
• Software and hardware sharing.
• Easier management and updates of network resources.

Disadvantages of LAN

• Installation/maintenance can be expensive.
• Requires a network administrator.
• Performance issues as more devices connect.
• Security vulnerabilities and risk of unauthorized access.

Basic Network Security

• Rules and protocols to restrict access and prevent misuse:
  • Use of usernames and passwords for access control.
  • Secure password management practices (e.g., complexity, changing regularly).

Choosing and Managing Passwords

• Best Practices:
  • At least 8 characters long.
  • Mix of upper and lowercase letters, numbers, and special characters.
  • Avoid easy-to-guess elements and keyboard patterns.
• Example of a good password: "Q1w2E3R4t%y"

Acceptable Use Policy (AUP)

• Establishes user rights and responsibilities in a network environment:
  • Defines access limits and acceptable online behavior.
  • Addresses issues like identity theft, malware, and cyberbullying.
  • Sets penalties for violations of the AUP.

Basic Netiquette Rules

• Restrictions on accessing online content.
• Guidelines on data downloads from the internet.
• Recommendations for safe and legal internet practices.

Summary

• Understanding the basic components of a network helps in managing its functionalities and security.
• Awareness of ethical use through policies and practices contributes to a safe network environment.