Ethernet Duplex

Understanding collision handling in full duplex Ethernet networks

This is an easy networking fundamentals question that tests whether you understand the practical difference between half-duplex and full-duplex Ethernet operation. It's the kind of question interviewers ask to confirm you grasp how modern switched networks actually work, rather than relying on outdated shared-medium intuitions.

The question requires you to reason about what happens when two devices communicate over a dedicated link with full duplex capability—that is, when both endpoints can transmit and receive simultaneously. To answer it correctly, you need to think through the collision-detection and arbitration mechanisms that apply in different network topologies and link configurations.

• Full duplex vs. half-duplex Ethernet modes
• Switched networks and dedicated links
• CSMA/CD (Carrier Sense Multiple Access with Collision Detection)
• When collision detection is and isn't necessary