Starting with the layer closest to the network media what is the correct order of the layers of the TCP/IP model?

Starting with the layer closest to the network media what is the correct order of the layers of the TCP/IP model?

• A. Network Access, Internetwork, Transport, Application
• B. Network Access, Internet, Transport, Application
• C. Physical, Network Access, Internet, Application
• D. Network Access, Internetwork, Transport, Application

Answer: (D)

The layer order in TCP/IP, from closest to the network medium upward, is Network Access, Internet (also called Internetwork), Transport, and Application. The Network Access layer covers the physical and data-link aspects that interface directly with the network medium, so it sits at the bottom. The next layer handles addressing and routing (the Internet layer). Above that is the Transport layer, which provides end-to-end delivery services (like TCP or UDP). At the top is the Application layer, where the actual user-facing protocols (HTTP, FTP, email, etc.) operate. So the correct sequence from the layer nearest the network to the highest layer is Network Access, Internet/Internetwork, Transport, Application. The idea that there would be a separate Physical layer isn’t part of the TCP/IP model, since physical and data-link functions are encompassed by the Network Access layer. Naming variations between Internet and Internetwork don’t change the order.

The layer order in TCP/IP, from closest to the network medium upward, is Network Access, Internet (also called Internetwork), Transport, and Application. The Network Access layer covers the physical and data-link aspects that interface directly with the network medium, so it sits at the bottom. The next layer handles addressing and routing (the Internet layer). Above that is the Transport layer, which provides end-to-end delivery services (like TCP or UDP). At the top is the Application layer, where the actual user-facing protocols (HTTP, FTP, email, etc.) operate.

So the correct sequence from the layer nearest the network to the highest layer is Network Access, Internet/Internetwork, Transport, Application. The idea that there would be a separate Physical layer isn’t part of the TCP/IP model, since physical and data-link functions are encompassed by the Network Access layer. Naming variations between Internet and Internetwork don’t change the order.