Although there are several different types and models of routers, every router has the same general hardware components.

The figure shows the inside of a Cisco 1841 first generation ISR. Click the components to see a brief description of the components.

Note that the figure also includes highlights of other components found in a router, such as the power supply, cooling fan, heat shields, and an advanced integration module (AIM), which are beyond the scope of this chapter.

Note: A networking professional should be familiar with and understand the function of the main internal components of a router, rather than the exact location of those components inside a specific router. Depending on the model, those components are located in different places inside the router.