In which network topology is a single central point failure (e.g., via a DoS—Denial of Service attack on the hub) most likely to disrupt the entire network?

The correct answer is Star Topology. In a star topology, all network devices are connected to a single central device, such as a hub, switch, or router. This central component is crucial because all data communication between any two nodes in the network must pass through it. Consequently, if this central device experiences a failure, becomes overloaded, or is targeted by a Denial of Service (DoS) attack, the entire network segment connected to it will cease to function. This makes the central device the single point of failure, meaning its compromise can bring down the entire network, making the star topology most susceptible to widespread disruption from such an event.

• Mesh Topology is incorrect. In a mesh topology, every device is connected to every other device, providing multiple redundant paths for data. This design is highly fault-tolerant; the failure of a single node or link typically does not disrupt the entire network, as traffic can be rerouted.
• Bus Topology is incorrect. In a bus topology, all devices share a single communication line (the bus). While a break in the main bus cable can disrupt the entire network, there isn't a single central active device like a hub that processes all traffic. Individual node failures do not necessarily affect the whole network.
• Ring Topology is incorrect. In a ring topology, each device is connected to exactly two other devices, forming a closed loop. While a single point of failure (a cable break or device failure) can disrupt a simple unidirectional ring, some implementations (like dual rings or token ring networks) offer redundancy to mitigate this. However, the question specifically refers to a central point of failure via a DoS attack on a hub, which is characteristic of a star.