The ROM Monitor (ROMMON) is a bootstrap program that (when functioning properly) initializes the hardware and boots the Cisco IOS XE software when you power on or reload a router. In the CLI, the switch prompts will display as Switch: to indicate that you are in this mode. This may happen if the switch detects an issue with the bin file or the patch linking to the file. I find that I need to remember how to recover a Switch with an IOS Tar File to resolve the issue.
