Huawei Certified Network Associate – Routing and Switching (HCNA-RS, legacy) — Question 41

Which of the following statements regarding layer-2 switch is incorrect?

Answer options

• A. The switch learns MAC addresses automatically.
• B. The layer-3 header is modified before the received packet is transmitted.
• C. The layer-2 header is modified before the received packet is transmitted.
• D. The layer-2 LAN switch operates at data link layer.

Correct answer: B

Explanation

Option B is correct because a layer-2 switch does not modify the layer-3 header; it operates at the data link layer and only processes layer-2 headers. The other statements accurately describe the functions of a layer-2 switch, such as learning MAC addresses and the operation at the data link layer.