An IOS image is a complete copy of Cisco IOS software that a compatible Cisco router or switch can load and run. Network administrators transfer images to a device when replacing its current software version. section 8.1 section 8.1.2
Devices commonly store IOS images in flash:. The IOS file system also exposes system: for the running configuration, nvram: for the startup configuration, and tftp: for network-based file access. Use show file systems and directory commands to identify storage locations and contents. section 8.1.2
Transfer and activate an IOS image with this operational sequence:
- Copy the image from a TFTP server with copy tftp: flash:, supplying the server address, source filename, and destination filename. section 8.1.2
- Use FTP when authentication is required; configure ip ftp username and ip ftp password, or provide credentials in copy ftp://username:password@server-ip flash:. section 8.2.2
- Verify that the new file exists in flash: with show flash: and distinguish it from the currently used image by its filename and listing. section 8.2.2
- Inspect the active version with show version, select the next boot image with boot system flash:/image-path, verify with show boot, save the configuration, and reload. section 8.3
Selecting a newly copied image
SW1(config)# boot system flash:/c2960c405-universalk9-mz.152-7.E7.bin SW1(config)# do show boot BOOT path-list : flash:/c2960c405-universalk9-mz.152-7.E7.bin After saving the configuration and reloading, show version confirms that SW1 runs Cisco IOS 15.2(7)E7 instead of 15.0(2)SE5.
