ccna 200 301 training

ccna 200 301 training.brackets at the end of the question) is correct, or you can press Enter to enter it. After that, if the command is received, the router clears the flash memory, copies the file, and then verifies the checksum (checksum) of the file to ensure that no errors occurred in the transfer.Once this is done, you can use the showHash command to verify the contents of the flash memory, as shown in Example 20-2. (The output of showflash will vary depending on the router family.)Example 20-2 Using the show flash Command, Verifying the Contents of Flash MemoryOnce the new version of the IOS is copied to flash memory, the router must reload the new IOS image. For example, in the output of Example 20-2, Router R2 has two IOS images in flash memory: the original Version 15.1 (4) image and the newly copied Version 15.2 (4) image. The next section focuses on the IOS boot sequence and explains in detail how to configure the router so that it can load the correct IOS image, including how to tell the router to start using the new IOS image. Tip: The IOS image is usually a compressed file, which takes up less space in memory. When the router loads the IOS image into RAM, itdecompresses it.Cisco IOS Software Boot SequenceCisco routers perform the same types of tasks that are performed when the computer is powered on, or rebooted (reloaded). However, many end-user computers install only one OS, so that the computer does not have to choose which os to load.In contrast, the router has multiple IOS images available on the flash and external TFTP servers, so the router needs a procedure to decide which IOS image to load into RAM for use. This section examines the entire boot process and focuses on the options that affect the router's choice of which IOS image to load. Tip: The details of the boot sequence in this chapter differ from those of the Cisco LAN switches, particularly with respect to the configuration registers and ROMMON OScontent, but they also apply to almost all Cisco router models. This book does not cover similar options in Cisco switches.When the router is first powered up, it follows these four steps.