chapter 9 ccna exam

chapter 9 ccna exam.. mz and z indicate that the image is compressed and must be uncompressed before it can be loaded/run. If you see a 1 here (the letter 1, not the number 1), it indicates where to run the IOS image from. A 1 means the image is removable and can also be run from RAM. Don't forget that depending on the router model, some images can be run directly from flash.. 124-6.T7 indicates the version number of the IOS software. In this example, the version is 12.4(6)T7 o The image with the name T contains new features, the image without T is the mainline version (only bugs are fixed) o. Finally, the .bin at the end indicates that this is a binary image.The naming conventions discussed here apply to IOS images that come with the IOS device, as well as to IOS images downloaded from the Cisco website. However, the name itself does not affect how the IOS image runs on the IOS device. For example, you can download an image from the Cisco website and rename it to pooq3erformance.bin, which will not affect the performance of the IOS device.16.3.2 Before Upgrading an IOS ImageThis section and the next section discuss how to upgrade and back up the IOS software on the router. Before upgrading the IOS on the device, it is important to back up the existing image to an external server for two reasons. First, the flash memory space may not be large enough to hold two images, one for the old image and one for the new image. If you have problems loading the new image, you may want to load the old image instead. Second, Cisco does not offer all software versions on its website. Older IOS versions are hard to find, so when upgrading from an older IOS version, it is highly recommended to back it up first.Before backing up the IOS image to an external server, be sure to do the following checks.. Use the command ping to check if the server is reachable.. Does the server have enough space for the IOS image? . Does the server support the file nomenclature you want to use?. Must there be a file on the server with the same name as the file you want to copy (some TFTPUNIX servers require this)? After performing these checks, you can start the backup.