The **TCP/IP model** is a framework used to visualise how data is organised and transmitted across a network. This model helps network engineers and network security analysts conceptualise processes on the network and communicate where disruptions or security threats occur. The TCP/IP model has four layers: *network access layer, internet layer, transport layer*, and *application layer*. When troubleshooting issues on the network, security professionals can analyse and deduce which layer or layers an attack occurred based on what processes were involved in an incident. ![[TCP-IP.png]] - [[Network Access Layer]] - [[Internet Layer]] - [[Transport Layer]] - [[Application Layer]]