In a company's network, every device is cabled to a central switch. One cable between a workstation and the switch is accidentally cut. What is the impact?
AThe entire network goes down because the central node is disrupted
BOnly the device connected by that cable loses network access
CAll devices experience degraded performance until the cable is replaced
DTraffic is automatically rerouted through other devices
A star topology isolates failures to the individual link — only the device connected by the severed cable loses access. The central switch continues operating normally and all other devices remain connected. This fault isolation is one of the main reasons star topology dominates home and office networks. Compare this to a bus topology where a cable break anywhere takes down all devices, or a mesh topology where traffic could reroute — but star topology has no rerouting, just isolation.
Question 2 Multiple Choice
A network administrator draws a diagram showing every device connected to a central switch (physical star). She then observes that the switch forwards every incoming frame out all ports simultaneously. What is the logical topology of this network?
AStar — because the physical layout determines the logical layout
BBus — because all devices receive every frame, just like a shared cable
CMesh — because the switch connects to all devices at once
DRing — because frames circulate through all devices before returning
Physical and logical topologies can differ significantly. The physical layout (star wiring to a hub/switch) does not determine the logical data flow. A hub that broadcasts every frame to all ports creates bus-like logical behavior — every device sees every message, just as in a physical bus. A modern *switch* (which sends frames only to the destination port) creates a logical point-to-point topology despite the same physical star wiring. This distinction is the key insight: what you see in the wiring closet does not necessarily tell you how data actually flows.
Question 3 True / False
In a full mesh topology, if a single link between two nodes fails, communication between those nodes becomes very difficult.
TTrue
FFalse
Answer: False
In a full mesh topology, every node has a direct connection to every other node, meaning multiple paths exist between any pair. If one link fails, traffic can be rerouted through intermediate nodes. This is precisely why mesh topologies are used in high-availability data centers and backbone networks — fault tolerance is built into the redundant paths. The statement describes what would happen in a bus or star topology, not a mesh.
Question 4 True / False
A star topology concentrates fault risk at the central hub or switch, making it a single point of failure for the entire network.
TTrue
FFalse
Answer: True
This is a genuine and important limitation of star topology. While a star isolates individual cable failures (only one device goes offline), failure of the central hub or switch takes down the entire network simultaneously. This is the classic 'single point of failure' tradeoff that network designers must weigh against star topology's advantages of easy management, fault isolation per node, and low cable cost. Redundant switches or failover designs are used in critical environments to address this.
Question 5 Short Answer
Why can physical and logical topologies differ, and why does this distinction matter for understanding network behavior?
Think about your answer, then reveal below.
Model answer: Physical topology describes how cables are physically laid out; logical topology describes how data actually flows between devices. They differ because network equipment like switches and hubs impose their own forwarding behavior on top of the physical wiring. A star-wired network using a hub behaves logically like a bus (all devices share bandwidth, every frame is broadcast to all); a star-wired network using a modern switch behaves like a mesh of point-to-point links (each frame goes only to its destination). The distinction matters because performance, security, and congestion behavior all depend on the logical topology — the physical wiring plan alone is insufficient to understand or troubleshoot how a network actually performs.
Administrators who only think about physical topology will misdiagnose network problems. Broadcast storms, collisions, and security vulnerabilities all depend on logical topology. Modern Ethernet switched networks are physically star-shaped but logically very different from the hub-based networks they replaced — understanding this was a major practical insight in network evolution.