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AS · Practice questions · Network topologies and hardware

Shape and boxes.

Six original Cambridge-style questions on topologies and network hardware, with mark-scheme style solutions.

Original questions All questions on this page are original work, written in the Cambridge AS & A Level style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

Follow the packet.

01
Explain
[4 marks]

Describe how a packet is transmitted from host A to host D in a star topology.

  • Host A sends the packet along its own cable to the central switch. ✓
  • The switch reads the destination (MAC) address in the packet/frame. ✓
  • The switch looks up which port host D is connected to. ✓
  • The switch forwards the packet only along the cable to host D (no other host receives it). ✓
02
Explain
[3 marks]

Describe how a packet is transmitted between two hosts on a bus network.

  • The sending host checks the backbone is free and transmits the packet onto it. ✓
  • The signal travels along the whole backbone and reaches every device. ✓
  • Each device checks the destination address; only the addressed host accepts it, and terminators absorb the signal at the ends. ✓
03
Apply
[4 marks]

A college is building a network across three buildings. Each building has its own switch with 30 computers. Name a suitable topology and justify your choice.

  • Hybrid topology. ✓
  • Each building is a star: a broken cable affects only one computer, and the switch sends packets only to the destination. ✓
  • The three switches are joined by a backbone (or mesh of links) between the buildings. ✓
  • It is easy to extend, and buildings can be added without redesigning the whole network. ✓
04
Recall
[4 marks]

State the purpose of each device: (a) WNIC (b) bridge (c) repeater (d) wireless access point.

  • (a) Allows a device to connect to a wireless network (sends and receives radio signals). ✓
  • (b) Connects two LAN segments using the same protocol so they act as one network. ✓
  • (c) Regenerates/boosts a signal so it can travel a longer distance. ✓
  • (d) Lets wireless devices connect to a wired network. ✓
05
Explain
[4 marks]

Describe the role and function of a router in a network.

  • Connects different networks together, e.g. a LAN to the internet / a WAN. ✓
  • Receives packets and reads the destination IP address. ✓
  • Uses a routing table to decide the next hop / best route and forwards the packet. ✓
  • Translates between private and public IP addresses (NAT) / may assign IP addresses using DHCP. ✓
06
Analysis
[3 marks]

Compare a switch and a router.

  • A switch connects devices within one network (LAN); a router connects different networks. ✓
  • A switch uses MAC addresses to forward frames; a router uses IP addresses to forward packets. ✓
  • A router chooses a route between networks (routing table); a switch forwards only to the device on the correct port. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.