Understand core networking concepts, components, topologies, and protocols.
Covers network component roles, topology architectures, physical interfaces and cabling, IPv4/IPv6 addressing and subnetting, TCP vs UDP, wireless principles, virtualization fundamentals, and switching concepts. This domain represents 20% of the CCNA exam.
5 minutes
5 Questions
Network Fundamentals form the foundation of the CCNA certification and cover essential concepts for understanding how networks operate. At its core, a network is a collection of interconnected devices that communicate and share resources. The OSI (Open Systems Interconnection) model provides a seven-layer framework for understanding network communication: Physical, Data Link, Network, Transport, Session, Presentation, and Application layers. Each layer has specific functions and protocols. The TCP/IP model, which is more practical, consists of four layers: Network Access, Internet, Transport, and Application. IP addressing is crucial for network communication. IPv4 uses 32-bit addresses divided into classes (A, B, C, D, E), while IPv6 uses 128-bit addresses to accommodate the growing number of connected devices. Subnetting allows network administrators to divide networks into smaller segments for better management and security. Network topologies describe how devices are arranged and connected. Common topologies include star, bus, ring, mesh, and hybrid configurations. Each has advantages and disadvantages regarding cost, reliability, and scalability. Ethernet is the dominant LAN technology, operating at various speeds including 10 Mbps, 100 Mbps, 1 Gbps, and 10 Gbps. It uses CSMA/CD for collision detection on shared media. Switches operate at Layer 2, using MAC addresses to forward frames, while routers operate at Layer 3, making forwarding decisions based on IP addresses. Network protocols enable communication between devices. TCP provides reliable, connection-oriented communication, while UDP offers faster, connectionless transmission. DNS translates domain names to IP addresses, and DHCP automatically assigns IP configurations to devices. Understanding these fundamentals is essential for configuring and troubleshooting networks, implementing security measures, and designing scalable network infrastructures that meet organizational requirements.Network Fundamentals form the foundation of the CCNA certification and cover essential concepts for understanding how networks operate. At its core, a network is a collection of interconnected devices that communicate and share resources. The OSI (Open Systems Interconnection) model provides a seve…