The IOS is stored in a memory area called flash. The flash allows the IOS to be upgraded or stores multiple IOS files. In many router architectures, the IOS is copied into and run from RAM. A copy of the configuration file is stored in NVRAM to be used during startup.
Where is permanent storage for the Cisco IOS stored?
Flash is used as permanent storage for the operating system, Cisco IOS. In most models of Cisco routers, the IOS is permanently stored in flash memory and copied into RAM during the bootup process, where it is then executed by the CPU.
Where is the fully functional IOS stored?
Flash memory: Flash memory contains the fully functional IOS images. It is the default location for getting IOS image at boot time.
Where does the Cisco IOS keep the startup configuration?
The running configuration is stored in RAM; the startup configuration is stored in NVRAM. To display the current running configuration, enter the show running-config command.
What is a Cisco IOS image?
Cisco Image Types
A boot image (also referred to as the xboot, rxboot, bootstrap, or bootloader) and the system image (the complete IOS image). The boot image is a subset of the Cisco IOS software that is used when network booting when loading IOS images onto a device or when the system image has been corrupted.
What is the difference between NVRAM and flash memory?
Flash memory content is retained by the router on power-down or reload. … RAM contents are lost when the router is powered down or reloaded. NVRAM is non-volatile RAM. By “non-volatile”, we mean that the contents of NVRAM are not lost when the router is powered down or reloaded.
What items are stored in RAM of a router?
The running configuration of the router is stored or held in the RAM. RAM is very fast in nature thus the running configuration is held in it. Any changes that are done in the configuration are stored in the RAM till it is saved to the NVRAM. The RAM stores the routing table, cache entries, IP packets buffer etc.
Which memory type holds the full IOS image for the router?
The Flash memory contains the full Operating System Image (IOS, Internetwork Operating System). This allows you to upgrade the OS without removing chips. Flash memory retains content when router is powered down or restarted.
What is Cisco IOS based on?
Cisco IOS is a monolithic operating system running directly on the hardware while IOS XE is a combination of a linux kernel and a (monolithic) application (IOSd) that runs on top of this kernel.