It is necessary to understand the communication models because fundamentally, the network traffic is assembled, packaged, and de-assembled based on these models.
Each protocol operates at a specific layer. Depending upon the protocols being used, the security controls are needed accordingly. This is the reason why one should have a good understanding of the layers of the TCP/IP model.
Before we start working on security controls, let's understand the basic architecture of the TCP/IP model:
![](https://static.packt-cdn.com/products/9781788299558/graphics/assets/34fc367b-844c-4273-9b25-a17a63026bf2.png)
In order to understand how exactly layering works, we will look at an example of a Wireshark packet capture.