Introduction
The Network Fundamentals module was a core part of my Cyber Security Degree, and it laid the foundation for understanding how computer networks operate. This module covered the material from the CCNA1 - Introduction to Networks (ITN), which is the first level of the Cisco Certified Network Associate (CCNA) certification. Networking concepts were a challenge for me, but they also piqued my interest because they form the backbone of most IT infrastructures. Understanding how networks operate is essential for a career in cybersecurity, as so many security issues arise from network configurations and communications.
Key Concepts Covered:
Routing & Switching: Routing and switching are fundamental concepts in networking that allow data to travel between devices across different networks. We learned how routers and switches work to forward data packets and establish connections. Routing is the process by which data is directed to its destination across networks, while switching happens within the same local network to direct data between devices. I became familiar with basic routing protocols such as RIP and OSPF and how switches use MAC addresses to make forwarding decisions. Understanding how routers and switches work together to form a network was critical to understanding more complex networking setups.
IPv4 & IPv6 Addressing: One of the main topics in the module was learning how IP addressing works, both for IPv4 and IPv6. We learned how to configure static and dynamic IP addresses, the structure of an IP address, and how subnetting works. IPv4 is still the most commonly used version of IP addressing, but we also discussed the growing need for IPv6 as IPv4 addresses are running out. We practiced subnetting IPv4 addresses to divide networks into smaller, more manageable segments, and explored how IPv6 is structured differently to accommodate a larger address space. Understanding both IPv4 and IPv6 was key for grasping how devices communicate over the internet.
The OSI & TCP/IP Model: The OSI (Open Systems Interconnection) and TCP/IP (Transmission Control Protocol/Internet Protocol) models are the conceptual frameworks used to understand network interactions. In this module, we focused on how different layers of the OSI model correspond to network operations, from the physical layer (hardware like cables and switches) all the way up to the application layer (such as web browsers and email clients). We also learned the TCP/IP model, which is more streamlined and commonly used in practice. I learned how data moves through these layers when it travels from one device to another, and how each layer provides specific services to the layers above and below it.
Network Topologies: Network topologies describe the physical or logical arrangement of devices in a network. The module covered different types of network topologies, including star, bus, ring, and mesh. We discussed the advantages and disadvantages of each topology and how they influence the network’s efficiency and fault tolerance. For example, in a star topology, all devices are connected to a central device (like a switch or router), while in a mesh topology, devices are interconnected. Understanding these topologies is essential for designing robust and efficient networks.
Intermediary & End Devices: In networking, devices are categorized as either intermediary devices (such as routers, switches, and firewalls) or end devices (like computers, printers, and servers). This module helped me understand the role of intermediary devices in directing traffic and maintaining the integrity of the network, as well as the role of end devices in initiating communication and using network services. I also learned about the importance of firewalls and security appliances in ensuring the protection and integrity of a network.
Building a Small Network: One of the most hands-on aspects of this module was building and configuring a small network. This exercise involved setting up routers, switches, and end devices, configuring IP addresses, and ensuring that all devices could communicate with one another. I gained practical experience in setting up network interfaces, configuring subnets, and testing the network to ensure that data was correctly routed between devices. This exercise gave me a deeper understanding of how networks are constructed in the real world and the steps needed to ensure their smooth operation.
Application of Concepts
The concepts covered in this module were directly applicable to real-world networking scenarios:
Routing & Switching: The knowledge of routing and switching allowed me to understand how networks are segmented and how traffic flows between different networks. In practice, this is critical for managing large-scale networks, as it helps ensure efficient data delivery and minimizes congestion.
IP Addressing: I learned how to subnet IP addresses, which is an essential skill for network configuration. This skill is vital for ensuring that IP address space is used efficiently and that devices on a network can communicate without conflicts. The hands-on practice with both IPv4 and IPv6 addressing also helped me understand the future direction of networking.
OSI & TCP/IP Models: Understanding these models helped me break down complex networking concepts into manageable layers. Each layer plays a specific role in enabling communication, and knowing how these models work has been instrumental in troubleshooting network issues.
Network Topologies: The study of network topologies gave me the ability to evaluate the most appropriate structure for a given network. This knowledge is essential for network design, as choosing the wrong topology can lead to inefficiencies, bottlenecks, and scalability issues.
Building a Small Network: The hands-on experience of building a small network reinforced my understanding of the theoretical concepts. I learned how to configure routers and switches, set up IP addresses, and test network connectivity. This practical experience has been invaluable in my development as a networking professional and will be essential for future networking projects.
Conclusion
The Network Fundamentals module was one of the most challenging yet rewarding parts of my Cyber Security Degree. It provided me with a solid foundation in networking concepts, from IP addressing and routing to network topologies and the OSI model. Although networking can be difficult to grasp, the hands-on experience and practical exercises in this module made the concepts more accessible. This module not only improved my understanding of networking protocols and technologies but also sparked my interest in pursuing more advanced networking and network security topics. With networking being at the core of most IT systems, the skills I gained in this module will be invaluable in my career as a cybersecurity professional.
Sources:
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