A star topology connects each node to a central switch; a mesh topology gives nodes multiple direct connections; and a hybrid topology combines two or more topologies. Therefore, star prioritizes simple centralized management, mesh prioritizes resilience, and hybrid balances requirements.
How Each Topology Works
In a star network, data travels through the central switch. One failed node cable disconnects only that node, but switch failure can stop the whole network because it is a single point of failure.
A full mesh connects every node directly to every other node; a partial mesh gives only selected nodes multiple links. Alternative routes increase fault tolerance, but extra cabling, ports, and configuration raise cost and complexity.
A hybrid design applies different topologies to different sections. For example, star subnetworks may connect through a mesh backbone, combining easy local administration with resilient communication between key sections.
| Factor | Star | Mesh | Hybrid |
|---|---|---|---|
| Structure | Central switch | Multiple direct links | Combined topologies |
| Resilience | Link failure is localized; switch failure is critical | High when alternative routes exist | Depends on its design |
| Cost | Moderate | High | Variable |
| Scalability | Easy if ports are available | New nodes may require many links | Can expand by section |
| Management | Centralized and simple | Complex | Flexible but potentially complex |
A common misconception is that a star's central device must be a server. It is normally a switch; a server is an endpoint that provides services rather than controlling the topology.
IB Exam Technique
For A2.2 Network architecture, a “compare” question requires similarities and differences, whereas “evaluate” requires a justified conclusion using scenario evidence. Link each topology to requirements such as budget, reliability, size, performance, and maintenance. Avoid stating that one topology is always best; the strongest answer selects a design and justifies its trade-offs.
