Which OSI layers map to the TCP/IP Link layer?

• A. OSI layer 3
• B. OSI layer 4
• C. OSI layers 5–7
• D. OSI layers 2–1

Answer: (D)

Understanding how TCP/IP's Link layer maps to the OSI model helps you see where data actually gets onto the network. The Link layer is responsible for framing, MAC addressing, and how the data is physically transmitted over the network medium. In the OSI model, those functions live in the Physical layer (layer 1), which handles the actual electrical/optical signals, and the Data Link layer (layer 2), which manages framing and MAC addresses. So the TCP/IP Link layer corresponds to OSI layers 1 and 2. The other options point to higher layers that deal with routing, reliability, or end-user application data, not the link-level housekeeping of framing and medium access.