Cisco Router Internal Components

The Internal Components of a Cisco Router

Computer contains RAM and Hard disk to save data on temporary and permanent basis. Just like a computer, Router also contains an operating system software (IOS) and also need to save data/configurations on temporary and permanent basis. I’ll explain you about the internal components of a Cisco router, so you could know what’s the exactly inside this magic box (Cisco Router).

Here’s a list of internal components of a Cisco router.

Mini-IOS - Cisco 

Cisco calls this bootloader. Mini-IOS is in the ROM (Read Only Memory) of router. Mini-IOS or bootloader brings up the interface and load the Cisco IOS into the Flash memory.

RAM (Random Access Memory)

RAM is temporary storage device of a router. All the running configurations of a router save in RAM. All the routing tables, caches are saved into RAM.

ROM (Read-Only Memory)

ROM is used for starting and maintaining the router. ROM is responsible for the mini-IOS and bootstrap programs.

Flash Memory

By default, Cisco IOS is saved in Flash memory. It’s not erasing when router is loaded.

NVRAM (Nonvolatile Memory)

NVRAM is a permanent storage device. Configuration register is in the NVRAM.