From the course: Learning the Packet Delivery Process

Learn the purpose of the network layer

From the course: Learning the Packet Delivery Process

Start my 1-month free trial Buy for my team

Learn the purpose of the network layer

“

- [Instructor] The network layer is the third of four layers in the TCP/IP model. The network layer makes it possible for data delivery to travel across the internet. It's sometimes called the internet layer for this reason. The main responsibility of this layer is to enable data to traverse any kind of network. And to make sure all data packets arrive at their destination. There are no rules that require these data packets follow the same path to their destination though. In fact, data packets generally do not. You can compare the entire process of data delivery, to relocating from one city to another. You must first deconstruct what you want to send and put all of your things in boxes. There are no specific rules for the types or size of boxes you use. But because boxes are the standard, you use them. Once your belongings are packaged properly you put those boxes into cars, moving trucks and maybe even airplanes, just like data delivery. You, the delivery company and the plane, all take different routes to the destination. And just like in data delivery, everything you've put into boxes must be reconstructed when they arrive. This is the purpose and job of the transport layer of the TCP/IP model. To manage the transport of data. The network layers use many protocols to get data from point A to point B. Here are some of the most common ones. IPv4 and IPv6, we've already mentioned. There's also Internet Protocol Security. Internet Protocol Message Protocol, and others. You already know, you can see a few of these protocols inside your Windows-based system, from a connections properties page. You can see more protocols in use from the firewall with advanced security window. I'll type firewall to bring this up and I'll click windows defender firewall with advanced security. I'll expanded this just a little to make it easier to see. And then let's have a look at the inbound rules section. That's here on the left. Let's look at the core networking entries, since we're talking about networking. You'll see the networking features that rely on ICMP, IGNP and more. First, let me sort by name and click on one of the core networking entries. Now I'll scroll over and I'll look for protocol. Then I'll drag this over, closer to the front, so we can have a better look. Here are some of the protocols used with core networking. Here's ICMPv4. And here's ICNPv6. You can see other protocols here, like UDP. You can continue to explore outgoing rules and other sections here, if desired. Although there are additional protocols used in the network layer and a lot more to learn. How protocols work and how they were created are far beyond the reach of this course. This is a good start though and leads us into the last layer of the TCP/IP model, the network access layer.

Contents