200-301 Question 77
Single answerA network administrator is troubleshooting connectivity issues between two switches. The administrator notices a high number of errors and collisions on one of the switch ports. Upon further investigation, they find that the port on Switch A is configured for full-duplex, while the port on Switch B is configured for half-duplex. What is the most likely cause of the issue?
- A
Duplex mismatch between the two switch ports
- B
The Ethernet cable is faulty and needs to be replaced
- C
The port on Switch A is operating at a higher speed than Switch B
- D
A spanning tree loop is causing the collisions
Show answer and explanation
Correct answer: A
Explanation
A duplex mismatch occurs when one device is set to full-duplex and the other to half-duplex. This configuration results in one device assuming it can transmit and receive simultaneously, while the other expects a shared transmission medium, leading to collisions, errors, and degraded performance. Correcting the duplex settings on both devices to match (either full-duplex or half-duplex) resolves the issue.
- A. Correct.
A duplex mismatch is a common cause of errors and collisions. One port in full-duplex mode can send and receive simultaneously, while the other in half-duplex mode cannot, leading to collisions and performance issues.
- B. Incorrect.
While a faulty cable could cause connectivity issues, it would not specifically result in duplex mismatch symptoms such as collisions and errors.
- C. Incorrect.
Speed mismatch can cause connectivity issues but would not directly cause the high number of collisions observed. Devices would likely fail to communicate altogether if the speeds are incompatible.
- D. Incorrect.
A spanning tree loop can cause network-wide issues but would not specifically explain the duplex mismatch symptoms observed in the described scenario.