organized (5)

Networks Affect Our Lives

• Communication is vital for survival, just like air, water, food, and shelter.

• Networks connect us in unprecedented ways, transforming our interactions.

Network Components

Host Roles

• Host/End Device: The devices such as computers and smartphones that connect to a network.

• Servers: Provide information to end devices.

  • Email Server: Runs email server software; clients access email via client software.

  • Web Server: Runs web server software; clients access websites through browsers.

  • File Server: Stores and shares files accessible by client devices.

Peer-to-Peer Networks

• Devices can function as both clients and servers.

• Advantages:

  • Easy to set up.

  • Lower cost and less complexity.

• Disadvantages:

  • No centralized administration.

  • Less secure and not scalable.

End Devices

• The origin and destination points for messages.

• Data transfers from one end device to another through the network.

Intermediary Network Devices

• Connect end devices and manage data traffic.

• Examples: Switches, routers, firewalls.

• Functions:

  • Regenerating signals.

  • Maintaining pathways.

  • Error notification.

Network Media

• Channels for communication in a network.

• Media Types:

  • Copper Cables: Use electrical impulses.

  • Fiber-Optic Cables: Utilize light pulses.

  • Wireless Transmission: Modulates electromagnetic waves.

Network Representations and Topologies

Network Representations

• Network diagrams represent devices using symbols.

• Important terms: Network Interface Card (NIC), Ports, Interfaces.

Topology Diagrams

• Physical Topology Diagrams: Show physical locations of devices and installation.

• Logical Topology Diagrams: Show addressing schemes and devices.

Common Types of Networks

Network Sizes

• Small Home Networks: Connect few devices.

• Small Office/Home Office (SOHO): Connects home or remote office with corporate networks.

• Medium to Large Networks: Connect many locations with numerous devices.

• World Wide Networks: Involve hundreds of millions of interconnected devices like the internet.

LANs and WANs

• Local Area Network (LAN): Spans a limited area, administered by one entity.

• Wide Area Network (WAN): Covers a larger geographical area and is typically managed by service providers.

The Internet

• A global connection of LANs and WANs, using various physical transmission methods.

• Institutions like IETF, ICANN, and IAB maintain its structure.

Intranets and Extranets

• Intranets: Private networks accessible only by members of an organization.

• Extranets: Provide access for outsiders needing secure access to organizational data.

Internet Connections

Internet Access Technologies

• Various technologies connect users to the internet:

  • Popular Home/SOHO Connections: Broadband cable, DSL, wireless WAN, mobile services.

  • Business Connections: Requires faster connections, such as leased lines and dedicated DSL.

Home and Small Office Connections

• Cable: High bandwidth, continuous internet connection from cable TV providers.

• DSL: High bandwidth from telephone lines.

• Cellular: Utilizes cell networks for internet access.

• Satellite: Ideal for remote areas.

• Dial-up: Basic, low bandwidth option.

Business Connections

• Corporates need:

  • Dedicated connections.

  • Higher bandwidth solutions like leased lines and Ethernet WAN.

The Converging Network

• Networks that deliver data, voice, and video services on the same infrastructure.

Reliable Networks

Network Architecture

• Factors supporting network data movement: Fault Tolerance, Scalability, Quality of Service (QoS), Security.

Fault Tolerance

• Minimizes failure impact by providing multiple data paths.

Scalability

• Enables quick and easy expansion without degrading service quality.

Quality of Service (QoS)

• Manages bandwidth distribution effectively, especially for voice and video services.

Network Security

• Includes infrastructure security and information security to protect data and access.

• Three goals of network security:

  • Confidentiality

  • Integrity

  • Availability

Network Trends

Recent Trends

• Networks must adapt to: BYOD (Bring Your Own Device), online collaboration, video communications, cloud computing.

Network Security

Security Threats

• Network security is crucial across all network sizes against external and internal threats.

• External threats: Viruses, denial-of-service attacks.

• Internal threats: Misuse or loss of devices.

Security Solutions

• Multi-layered security solutions include antivirus, firewalls, and intrusion prevention systems for larger networks.

The IT Professional

CCNA Certification

• Demonstrates foundational knowledge of networking technologies and skills relevant to evolving needs, including IP, security, and wireless.

Networking Jobs

• Opportunities can be found through platforms like NetAcad.

Module Practice and Quiz

• Key learnings from the module include: network communication essentials, network types (LANs, WANs), IP addressing, basic security practices.

Memorization Points

1. Host Roles: End Device, Servers (Email, Web, File).

2. Peer-to-Peer Advantages: Easy setup, low cost; Disadvantages: No central admin, less secure.

3. Network Differences: LAN vs. WAN.

4. Internet Access Types: Cable, DSL, Cellular, Satellite, Dial-up.

5. Security Goals: Confidentiality, Integrity, Availability.