How Can I Lock an Operating Terminal?
Using the lock command, you can lock the current user interface to prevent unauthorized users from operating on the terminal screen. User interfaces include those of the console port, AUX port, and VTY.
When you run the lock command, the system prompts you to enter a password for the screen saver twice. If the two passwords are the same, the current user interface is locked successfully. To enter the system, press Enter and input the password as prompted. Enter the password specified just now, you can unlock the user interface and enter the system.
For example, a user logs in through the console port and locks the current user interface.
Note that only the current terminal is locked. For example, if you use Telnet on a terminal to log in to a device, only the current terminal is locked. You can still use other terminals to telnet to the device. The locked terminal does not exist the lockout interface even if the timeout has expired. That is, you must enter the unlock password to use the terminal again.