We finished our last post writing about the Transport Layer of the OSI Reference Model of the network. Now, I’m going to summarize the Internet & Network layers of such model.

Internet Layer.

The Internet layer primarily defines the Internet Protocol (IP) and defines IP addressing, so, that devices can have its own unique IP. In addition, the Internet layer defines the process of routing to let routers deliver packets of data to the correct destination.

The data encapsulated in the Internet layer is a called a packet.

Network Layer.

The Network access layer defines the hardware and protocols required to deliver data across some physical network. It includes all the variations of Ethernet protocols, PPP and Frame Relay.

The data including Ethernet header/trailer and PPP header/trailer in the Network layer is called a frame.

In a brief, the TCP/IP model consists of the following layers:

  • Application
  • Transport
  • Internet
  • Network Access

The next post of this CCNA crash course will about the OSI reference model of the network.