Introduction to Networks - Module 1 Notes

Course Overview

• Part of Cisco NetAcad's Introduction to Network course.
• Topics include:
  • Impact of networks on daily life.
  • Network components and devices.
  • Network representations and topologies.
  • Types of networks (LANs, WANs) and characteristics.
  • Reliable networks - four basic requirements.
  • Current network trends (BYOD, cloud computing, etc.).
  • Basic security threats and solutions.
  • Career opportunities in networking (Network Engineer, Analyst).

Importance of Networks

• Communication is essential, especially highlighted during COVID-19.
• Networks create a world without boundaries - enabling global workforces.
• Example: Work from home via VPN, connecting to a company's network remotely.

Network Components

Host and End Devices

• Host/End Device: Every computer on a network.
• Servers: Provide information to end devices (e.g., email servers, web servers, file servers).
• Clients: Devices that request information from servers.

Intermediate Devices

• Devices that interconnect end devices:
  • Switches
  • Routers
  • Wireless Access Points
  • Firewalls
• Manage data flow and maintain network pathways.

Peer-to-Peer Networks

• No central control, typically insecure and not scalable.
• Mainly used for direct connections between devices (e.g., printing).

Network Media

• Wired Media: Traditional metal wires (Cat5/Cat6) and fiber optics.
• Wireless Media: Communicates via electromagnetic waves (less secure than wired).

Network Representations and Topologies

• Network Diagrams: Symbols represent devices for easier comprehension.
  • NIC (Network Interface Card): Physical connection to the network.
  • Physical Topology: Illustrates physical device locations.
  • Logical Topology: Illustrates how devices are interconnected.

Common Types of Networks

• LAN (Local Area Network): Small geographical area.
• WAN (Wide Area Network): Larger geographical area, connecting multiple LANs.
• SOHO (Small Office/Home Office): Connects to corporate networks.

Internet Connections

• Home and small office:
  • Cable
  • DSL
  • Cellular
  • Satellite
  • Dial-up (less common today).
• Business Connections:
  • Dedicated lease lines (T1, T2).
  • Business DSL, Metro Ethernet.

Reliable Networks

Characteristics of Reliable Networks

1. Fault Tolerance:
   • Limits impact of failures, provides redundancy through packet switching.
2. Scalability:
   • Expand without impacting performance, adding devices easily.
3. Quality of Service (QoS):
   • Prioritizes data flow for sensitive services like video and voice.
4. Security:
   • Protects physical and data integrity through encryption and access controls.

Current Network Trends

• BYOD (Bring Your Own Device): Allows personal devices on corporate networks.
• Online Collaboration: Tools like Cisco WebEx, MS Teams for joint projects.
• Video Communication: Essential for remote work.
• Cloud Computing: Services like Office 365 offer reliability without physical servers.

Network Security

Threats

• External Threats: Viruses, denial of service attacks, etc.
• Internal Threats: Misuse by employees, lost devices.

Security Solutions

• Layered security: Antivirus, firewalls, intrusion detection, and VPNs.

Career Opportunities in Networking

• Certifications: CCNA (Cisco Certified Network Associate) and CCNP (Cisco Certified Network Professional).
• Skills focus: IP foundation, security, wireless, virtualization.

Summary

• Networks connect us universally, facilitating communication.
• Understanding network components, topologies, and security is essential for IT professionals.
• The knowledge gained is applicable to everyday life and career opportunities.