Another possibility among those listed by Pala is the debug cli command. Those commands can be used to access some internal information on the system, enable/disable some features (trial license for example), etc.
They are harmless if you use show commands, and can help you troubleshoot an issue, if you know how to use them and interpret the result. I'd recommend to let GTAC guide you in the event you need to do that. Some of the debug commands are accessible, some are hidden.
You also have the possibility to configure debug-level log entries. But again, I won't encourage you to do so without GTAC asking for it in a controlled manner. That can become harmful if misused.
Finally, there's a debug mode in EXOS, but you can't access it without GTAC generating a one-time password, valid for a few hours only. From there, full access to the internal of EXOS and the HW is provided. And this is not anymore the EXOS commands you know. This is only for GTAC. This is for troubleshooting only.
