Customer will not see the license that they wanted to re-use in the list of available license keys displayed by the lastline_register command.
NSX NDR
If a customer wants to re-use a license key from an appliance they are replacing, they must first de-register the appliance and then they can delete it from the Portal UI.
The instructions for de-registering an appliance are in the Appliance Installation Guides under Reregistration.
Sensor Reregistration Link: https://user.lastline.com/install-manuals/Sensor_Installation_Manual.html#reregistration
Engine Re Registration Link : https://user.lastline.com/install-manuals/Engine_Installation_Manual.html#reregistration
Please raise a support request If finding any difficulty.
NSX Defender API Documentation
https://user.lastline.com/papi-doc/api/html/index.html
API Calls Used
/papi/accounting/appliance/list_registered
https://user.lastline.com/papi-doc/api/html/accounting/overview.html#accounting.appliance.get_registered_appliances
/papi/accounting/appliance/deregister.json
https://user.lastline.com/papi-doc/api/html/accounting/overview.html#accounting.appliance.deregister_appliance
Note: This article is applicable to the standalone NSX Network Detection and Response product (formerly Lastline) and is not intended to be applied to the NSX NDR feature of NSX-T.