Cisco devices usually use integrated flash memory to store IOS software images and other files (e.g. backup configuration files). The startup configuration is stored in NVRAM. For each memory device available on the device, a file system called IOS file system (IFS) is created. To list file systems available on your device, the show file systems EXEC mode command is used: Show R1#show file systems
File Systems:
Size(b) Free(b) Type Flags Prefixes
* 255744000 221896413 disk rw flash0: flash:#
262136 255005 nvram rw nvram:
In the command above you can see that I have two file systems available on my device. Here is a description of each field:
The IOS image is a single file that is loaded into RAM when the device boots. This file is usually stored in the flash memory, since this type of memory will retain the stored files even after the router is powered off or rebooted. To show the contents of the flash memory, the show flash: command is used: R2#show flash: System flash directory: File Length Name/status 3 33591768 c1900-universalk9-mz.SPA.151-4.M4.bin 2 28282 sigdef-category.xml 1 227537 sigdef-default.xml [33847587 bytes used, 221896413 available, 255744000 total] 249856K bytes of processor board System flash (Read/Write) The file c1900-universalk9-mz.SPA.151-4.M4.bin is an IOS image for the 1900 Integrated Services Router series. The other two XML files are used for encryption purposes. Download our Free CCNA Study Guide PDF for complete notes on all the CCNA 200-301 exam topics in one book. We recommend the Cisco CCNA Gold Bootcamp as your main CCNA training course. It’s the highest rated Cisco course online with an average rating of 4.8 from over 30,000 public reviews and is the gold standard in CCNA training: Cisco IOS images are copyrighted, you need a CCO log on to the Cisco website (free) and a contract to download them. There are others ways for getting them but advising you of that would be against Cisco’s legal protection and I do a lot with Cisco and so will not suggest them. What is Cisco Dynamips? Dynamips is an emulator computer program that was written to emulate Cisco routers. Dynamips runs on FreeBSD, Linux, Mac OS X or Windows and can emulate the hardware of the Cisco series routing platforms by directly booting an actual Cisco IOS software image into the emulator. What is idle PC value in gns3?The Idle-PC is a guess at where the Program Counter might be pointing to an idle-loop in the emulated router. When emulator has visits this PC value Idle-Max times, it suspends itself for Idle-Sleep ms to allow other processes to get on their tasks. What is the difference between NVRAM and flash memory? Flash is erasable and reprogrammable ROM. 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. 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 are the features of Cisco 3700 series access points?The 3700 series provides high reliability and overall wireless performance. The 3700 series offers dual-band radios (2.4 GHz and 5 GHz) with integrated and external antenna options. The access points support full inter-operability with leading 802.11ac clients, and support a mixed deployment with other access points and controllers. Is the c7200 series compatible with iOS 15? It is a free-ware software. IOS 15.x – Only the c7200 series get newer IOS 15 images. All other platforms are now end-of-life and only support IOS 12.4. Please note that the IOSv appliance is based on IOS 15 and there are IOU (IOS on UNIX) images with IOS 15. Which is the best version of Cisco IOS? Its always better to use latest IOS versions, as they provide full command support. If you can’t buy original routers and switches, GNS3 is your rescue. What kind of radio does the Cisco 3702e have?For information on the regulatory domains, see “Regulatory Domains” section. The 3702E model is configured with up to four external dual-band dipole antennas, and two 2.4-GHz/ 5-GHz dual-band radios. The radio and antennas support frequency bands 2400–2500 MHz and 5180–5865 MHz through a common dual-band RF interface. Where is IOS stored in a Cisco switch?RAM On a router, RAM is used to hold IOS system tables and buffers. NVRAM is used to store the startup configuration.
Where does the bootable IOS image is stored on a Cisco router?Cisco IOS is stored in memory area called flash. And if flash memory is empty router will try to use TFTP to load an IOS image from stored Rom. Flash is used for permanent storage of a full Cisco IOS software image in compressed form(. bin).
Where does the Cisco IOS keep the startup configuration?There are two configurations stored in a Cisco router; the startup configuration is stored in nonvolatile RAM (NVRAM) and is only read when the router “starts” up; the other is the running configuration and it is stored in RAM while the router is operating.
Where is the startup configuration file stored?A startup configuration is stored in the nonvolatile memory of a device, which means that all configuration changes are saved even if the device loses power.
|
