The Application Layer

The Application Layer deals with the protocols required to have process-to-process communication.

In the following screenshot, we can see that we have used the HTTP protocol in this layer, and there are various headers associated that will help the destination application to understand and exchange the data:

The core protocols in this layer are HTTP, SMTP, FTP, and DNS.

This is a high-level overview of the TCP/IP model. We looked into packets as well to see how they are constructed to follow the layered-based model.

All the devices related to network security, such as firewalls, IDS/IPS, and WAF read the data from the packets of these layers and depending on the data, the rules are applied. This is the reason why we revised the TCP/IP before continuing further.

Now that we understand the basics about these layers, we will move on with a more practical approach to network security.