Basic Networking
Domain 6: Basic Networking
This domain covers how computers share data and resources. Questions ask about network types, topologies, devices, media, addresses, and simple troubleshooting. You should be able to choose an appropriate network for a school lab or small office and explain why.
Core rules and concepts
- A network links devices to share files, printers, and Internet access. By size: PAN (personal), LAN (building/campus), MAN (city), WAN (country/global). The Internet is the largest WAN.
- Topologies: bus (single backbone, cheap, fails widely), star (central switch/hub, easy fault isolation), ring (closed loop), mesh (redundant, costly). Most LANs use star.
- Devices: hub broadcasts to all ports; switch forwards by MAC address; router connects networks and routes by IP address; modem converts signals for ISP access; access point provides Wi-Fi.
- Media: twisted-pair Ethernet cable, coaxial, fibre-optic, and wireless. Bandwidth is capacity; latency is delay.
- Addressing: MAC is a hardware address; IPv4 is a logical address. DNS resolves names; DHCP assigns IP addresses automatically. Client-server and peer-to-peer are common models.
Worked example
Question: A 20-computer school lab needs Internet and shared printing with minimal disruption when one cable fails. Which topology and central device? Reasoning: Use star topology with a switch. Each PC has its own cable to the switch; one failed cable affects only that PC. The switch connects to a router for Internet access and to a shared printer or print server. A hub would still work but causes unnecessary collisions; a bus would make one break disruptive.
Traps that cost marks
Do not say a router and modem are the same. Do not confuse MAC with IP. Do not call a hub intelligent-it does not learn addresses. Do not claim Wi-Fi is a topology; it is a transmission medium. Do not ignore the printer’s network configuration.