Local Area Networks (LANs)

May 29, 2024

Local Area Networks (LANs)

Definition & Types of Networks

  • Network: Two or more computer devices connected through some media for sharing information.
  • Types of Networks:
    • PAN: Personal Area Network; around an individual.
    • HAN: Home Area Network; within a home environment.
    • LAN: Local Area Network; small area, generally one building.
    • Internet: Worldwide computer network.
    • Intranet: Organization’s private network.

Network Components

  • Clients and Servers:
    • Server: Powerful computer providing services to clients in the network.
      • Types of Services: File services, email, internet, web server, print server, database server.
    • Clients: Devices like desktops, laptops, tablets, smartphones using server services.
  • Identifying Network Connection:
    • Extra drives in File Explorer.
    • Network activity indicator in the notification area.

Network Hardware

  • Network Interface Controller (NIC):
    • Network card; built into laptops/desktops.
    • Types: Wired and wireless adapters.
  • Switches:
    • Connect computers in a network for communication.
    • Example: Connecting PCs, laptops, and printers to a switch which connects to a server.
  • Routers:
    • Provide wireless connectivity.

LANs

  • Wired LANs: Limited to one geographical area.
  • Wireless LANs (WLANs):
    • Easier to install between buildings.
    • Disadvantages: Security risks, possible performance reduction, signal loss/interference.

Communication Methods

  • Cabled Networks:
    • UTP (Unshielded Twisted Pair), STP (Shielded Twisted Pair), and fiber optic cables.
    • UTP Categories (e.g., cat 5, cat 5e, cat 6).
    • Fiber optic: Uses light signals for longer distances, not affected by electrical sources.
  • Wireless Networks:
    • Wireless access points and adapters.
    • Wireless typically slower than wired due to signal consistency.

Network Software

  • Role: Controls communication and security in a network.
  • Operating Systems: Most have built-in networking capabilities. Server editions for larger networks.

Advantages & Disadvantages of LANs

  • Advantages:
    • Transfer files without physical devices.
    • Shared software and hardware.
    • Central file storage.
  • Disadvantages:
    • Expensive installation and maintenance.
    • Requires network administration.
    • Wireless-specific: Security risks, performance issues, signal interference.

Network Topologies

  • Bus Topology: One main cable connects all computers.
  • Star Topology: Each computer connects to a central switch.
  • Ring Topology: Computers connected in a circular fashion; data travels one way.
  • Mesh Topology: Every node connects directly to every other node; high reliability but complex.

Basic Network Security

  • Goals: Prevent unauthorized access and network misuse.
  • Measures:
    • Restrict access to confidential files.
    • Use usernames and passwords for network access.
    • Password guidelines: At least 8 characters, mix of letters, numbers, special characters, change regularly.

Ethical Use of Networks

  • Acceptable Use Policy (AUP):
    • Defines rights and responsibilities of users.
    • Includes rules on data access, usage limits, and restrictions on installing hardware/software.