Cisco – Factory Reset Cisco 3560: Stuck in loop

ciscocisco-catalystcisco-ios

I recently acquired a used Cisco Catalyst 3560 and I am trying to factory reset it. When I enter the recovery process (by holding MODE), I get stuck in this loop at the "switch: " prompt.

Screen Capture of PUTTY

How do I resolve this issue?

Best Answer

Sounds like a nice job of a botched content ot the boot variable - possibly the config file variable. The switch: prompt you see there is called the ROMMON prompt. ROMMON is a bit like the BIOS of a PC, but a lot simpler.

Your switch seems to fall back into bootloader/rommon continously because something after the bootloader phase is failing. The most common cause for that is: IOS Software image not readable/loadable at the location give in the boot directive/boot variable.

Using information from here... https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/command/reference/3560cr/bootldr.html

... I suggest you proceed as follows:

  • use the mode button procedure during power-up to force the switch into bootloader/rommon, avoiding a full boot attempt.
  • use flash_init to make the flash filesystem availabe/readable
  • use set (no parameters or options) to see the environment variables during the rommon/bootloader stage. It will tell you which file is being searched as IOS image to boot, or if there is a directive to read a particular config file (which might be missing). Please note: the variables here (e.g. IP address, Mask, Gateway to boot via TFTP) are only meaningful for the boot process, they have nothing to do with the configuration of the switch when it will eventually run and load its config file.
  • use dir <filesytem> (probably as dir flash:) to see if that or another IOS image file is available somewhere in the flash filesystem.
  • use set <variable> or unset <variable> commands to manipulate variables as you see fit, or...
  • use boot flash:/<iosimagefile> to force the loading of the given IOS image file1

Then, when booted, make sure that in running-config and/or startup-config, the boot system flash flash:/iosimagefilename directive points to a file that actually exists - or is blank. An empty boot file directive usually works, because the switch will usually attempt to boot from the first available IOS-image on flash.

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