Topology describes how nodes and links are arranged — it affects redundancy, cost, collision domains, and failure modes. Logical topology (how data flows) can differ from physical cabling (how wires run).
Compare classic LAN shapes
⭐
Star
━
Bus (legacy)
⭕
Ring logical
🕸️
Mesh (full/partial)
🌳
Hierarchical tree
🔀
Hybrid
Physical layout vs logical path
Campus core
🔌Access SW
🔌Access SW
📶Distribution
🧠Core mesh
Quick selection guide
| Topology | Pros | Cons |
|---|---|---|
| Star | Simple, scalable, easy fault isolation | Core dependency without redundancy |
| Bus | Minimal cable (historical) | Collisions, hard troubleshooting |
| Full mesh | Maximum path redundancy | Expensive N² links |
| Tree | Clean aggregation, policy zones | Careful STP tuning if Layer2 loops |
How Ethernet topologies evolved
Shared bus
1980s
10/100 hubs
1990s
Switched star
2000s+
Leaf-spine DC
Today
✅Modern access is almost always physical star to a switch; logical topology is determined by VLANs, routing, and overlays running on top.