Hands-On Network Fundamentals: OSI, TCP/IP, and VPNs in Practice
Eldon Gabriel
Eldon Gabriel

Tags

  • cybersecurity
  • fundamentals
  • networking
  • osi
  • tcp-ip
  • vpn

The more you learn network fundamentals, the easier cybersecurity gets. Completing the Network Fundamentals section of the MSAF course was not just a checklist item—it was a milestone in my journey. This module involved hands-on labs that applied theory to real-world scenarios, mirroring the exact skills required by cybersecurity professionals.

Grasping the Theoretical Underpinnings

I began by building a strong foundation through research on the OSI and TCP/IP models:

  • OSI model: A 7-layer framework for understanding network communication.
  • TCP/IP model: The practical 4-layer model powering the Internet.

Understanding each layer is essential for spotting vulnerabilities, analyzing traffic, and implementing security controls.

Next, I researched common networking hardware used in enterprise networks:

  • Hubs: “Dumb” devices that broadcast traffic to all ports.
  • Switches: Targeted traffic delivery, more efficient than hubs.
  • Routers: Manage traffic between networks.
  • Firewalls:** Protect sensitive data by controlling access and segmenting networks.

Putting Knowledge into Practice: Static & Dynamic Network Design

To test my knowledge, I designed a visual network with Draw.io for a 100-employee business. Every PC, switch, and server placement built the network; adding firewalls and a DMZ protected it. The result: a complete network diagram with secure segmentation and proper security controls.

The final challenge involved Cisco Packet Tracer to create a dynamic network for a 1,000-employee organization. Tasks included:

Tasks Included

  • Building WANs, LANs, and VLANs.
  • Configuring Access Control Lists (ACLs) and Network Address Translation (NAT).
  • Establishing an IPSec VPN tunnel, troubleshooting crypto parameters, and resolving command-line quirks.

This exercise took over 10 hours of intensive hands-on work and led me to create a troubleshooting guide for the final diagram.

Key Tasks Completed

  • Researched the OSI and TCP/IP models and cybersecurity implications.
  • Researched common networking hardware for enterprise networks.
  • Designed a static network diagram using Draw.io.
  • Built a dynamic network in Cisco Packet Tracer.
  • Configured LANs, VLANs, ACLs, NAT, and IPSec VPNs.

ℹ️ Note: Full lab reports and video submissions are available upon request.

Conclusion

Textbook learning alone does not prepare you for advanced hands-on exercises like this. I gained practical, real-world skills and produced a complete two-part network project suitable for my cybersecurity portfolio.

Key Takeaways

  • Hands-on experience designing static and dynamic networks.
  • Learned to set up LANs, VLANs, ACLs, NAT, and VPNs.
  • Built troubleshooting and documentation skills under real-world conditions.
  • Applied OSI and TCP/IP theory directly to practical scenarios.
  • Produced a portfolio-ready two-part network project.

Ethical Disclosure

ℹ️ Note: In line with my academic pledge at Mossé Cyber Security Institute (MCSI), official course solutions are not published. Instead, these posts reflect my independent work and interpretation of industry-relevant skills and tools. Supporting documentation is available privately for recruiters, mentors, or collaborators.