After we successfully imported device list from ITNM, the TNCM started auto-discovery to import the configurations of those devices. However only the Juniper EX4500 switches which the smart driver (version 14) supports, can be imported successfully. Then we managed to work around it by manually removing the failed one and manually importing them with the same names in the TNCM native GUI. But this work around is OK for a POC but not for production where thousands of devices exist.
We assume this issue is caused by the support coverage of smart driver. So as long as the smart driver can support the device, then this issue won’t happen. But we are not sure if such assumption is correct.