This article showcases how to take a USG FLEX out of your Nebula Organization.
Note: When executing either a hardware reset or an un-registration, you will have to repeat the entire ZTP process - the device will boot up its system-default configuration. This could lead to undesired effects, especially if the device is not locally reachable.
How to set USG Flex back to standalone mode.
Just simply navigate to Nebula cloud center and find the device in the path
Organization-wide > Inventory
As in the below figure, check the checkbox then click the “Unregistered” button it will pop up the confirmation page click OK to continue.
You will also then have to confirm the un-registration process:
Again, as stated above, USG Flex will immediately reset to factory default and reboot once the unregistered, you will see the SYS LED start blinking, after it becomes steady green then it has turned to the standalone mode.
In order to get the USG FLEX back into Nebula, you will have to restart the ZTP-Process again: How to register a USG FLEX series on Nebula Control Center (NCC)