Networking & Infrastructure

Networking, also called computer networking, is the practice of transporting and exchanging data between nodes over a shared medium. It encompasses the design, construction and operation of the network infrastructure, plus the management and maintenance of hardware, software and policies. Networks connect devices and users—whether on a small LAN or across the internet—so they can share resources, communicate and access services. Everything from telephone calls and messaging to streaming video and the internet of things relies on networking.

Types and uses of networks

• Local Area Networks (LANs): Interconnect devices within a limited area such as an office or home. LANs enable file sharing, printers and local servers for employees or family members.
• Wide Area Networks (WANs): Connect multiple LANs over long distances (cities, states or countries) to link branch offices, data centres and remote users.
• Metropolitan/Campus networks: MANs and CANs span a metropolitan region or university campus, providing high‑bandwidth connectivity across multiple buildings.
• Storage Area Networks (SANs): Dedicated networks connect servers to storage devices for high‑speed data access and disaster recovery.
• Wired vs Wireless: Wired networking uses copper or fibre cabling for speed, reliability and security, whereas wireless networking uses radio waves (Wi‑Fi, cellular, Bluetooth) to provide flexibility and mobility.
• Virtual & overlay networks: Technologies like VLANs and software‑defined networking (SDN) create logical networks on top of physical infrastructure, enabling segmentation, automation and programmability.
• Cloud networks: Public and private cloud environments provide networking resources hosted off‑site. Hybrid and multi‑cloud architectures connect on‑premises systems to cloud services for scalability and global reach.

Fundamental Concepts

• TCP/IP & OSI model: Understand how data flows through layers—from physical transmission to application protocols. The OSI model divides networking into seven layers (physical, data link, network, transport, session, presentation and application) to guide troubleshooting and design.
• IP addressing & routing: Assign IP addresses, design subnets and configure routing tables so packets find their way between networks. Protocols like BGP and OSPF determine the best path for data.
• DNS & DHCP: Domain Name System translates human‑friendly domain names into IP addresses, while Dynamic Host Configuration Protocol automatically assigns network settings to devices.
• Network security: Firewalls, intrusion detection systems and access control lists filter traffic and enforce security policies. Virtual private networks (VPNs) encrypt data for secure remote access.
• Performance & reliability: Load balancers distribute traffic across multiple servers, and high‑availability designs ensure systems remain operational during failures. Quality of Service (QoS) mechanisms prioritise critical traffic.
• Software‑Defined Networking (SDN): Separates the control plane from the data plane, enabling centralised management, automation and rapid reconfiguration of network devices.
• Network topologies: The arrangement of nodes and links—such as star, mesh, bus and ring topologies—influences scalability, resilience and performance. Modern networks often use hybrid or hierarchical designs.

Benefits

• Security: Proper segmentation and access controls protect sensitive data and systems from unauthorised access.
• Performance & reliability: Efficient routing, load balancing and redundancy improve responsiveness and ensure continuous operation.
• Scalability: Modern networking technologies adapt to growing workloads and changing business requirements.
• Connectivity & collaboration: Networks enable employees, customers and devices to share information and resources from anywhere.

Free Resources

• Cisco Networking Academy – Free courses covering networking fundamentals and certification preparation.
• Wireshark – Open‑source network protocol analyser.
• OpenVPN – Open‑source VPN for secure remote access.
• GNS3 – Free network emulator to design and test complex network topologies.
• Mininet – Emulates software‑defined networks for research and learning.