The purpose of the auto-upgrade feature is to allow a switch to be upgraded to a compatible software image, so that the switch
can join the switch stack.
When a new switch attempts to join a switch stack, the active switch performs the compatibility check. Each stack member
sends the results of the compatibility checks to the active switch, which uses the results to determine whether the switch can join the switch stack. If the software on the new switch is incompatible
with the switch stack, the new switch enters version-mismatch (VM) mode.
If the auto-upgrade feature is enabled on the existing switch stack, the active switch automatically upgrades the new switch with the same software image running on a compatible stack member. Auto-upgrade starts
a few minutes after the mismatched software is detected before starting.
Auto-upgrade is disabled by default.
Auto-upgrade includes an auto-copy process and an auto-extract process.
Auto-copy automatically copies the software image running on any stack member to the new switch to automatically upgrade
it. Auto-copy occurs if auto-upgrade is enabled, if there is enough flash memory in the new switch, and if the software image
running on the switch stack is suitable for the new switch.
A switch in VM mode might not run all released software. For example, new switch hardware is not recognized in earlier versions
Automatic extraction (auto-extract) occurs when the auto-upgrade process cannot find the appropriate software in the stack
to copy to the new switch. In that case, the auto-extract process searches all switches in the stack for the bin file needed
to upgrade the switch stack or the new switch. The bin file can be in any flash file system in the switch stack or in the
new switch. If a bin file suitable for the new switch is found on a stack member, the process extracts the file and automatically
upgrades the new switch.
The auto-upgrade feature is not available in bundle mode. The switch stack must be running in installed mode. If the switch
stack is in bundle mode, use the request platform software package expand switch all file tftp://x.x.x.x/image.bin to flash: auto-cop privileged EXEC command to change to installed mode.
You can enable auto-upgrade by using the software auto-upgrade enable global configuration command on the new switch. You can check the status of auto-upgrade by using the show running-config privileged EXEC command and by checking the Auto upgrade line in the display.
You can configure auto-upgrade to upgrade the new switch with a specific software bundle by using the software auto-upgrade source url global configuration command. If the software bundle is invalid, the new switch is upgraded with the same software image
running on a compatible stack member.
When the auto-upgrade process is complete, the new switch reloads and joins the stack as a fully functioning member. If you
have both stack cables connected during the reload, network downtime does not occur because the switch stack operates on two