When adding systems into TPAM, TPAM only requires that the System Name must be unique. No validation is done to prevent a Managed System for the same platform type being created by IP and also by DNS name in error.
Adding a Managed System twice (for example, by IP and by DNS name) for the same Platform type in error can have significant and unexpected consequences. Consider a Managed System within TPAM attempting to manage the same accounts on this system, when System_A (IP) first changes the passwords on any managed accounts, these accounts will become out of sync with the same account from System_B (DNS name).
In an expected configuration, having a Managed System entered twice (for example, once by IP and also by DNS name) for the same Platform type will be a configuration error that should be reviewed and corrected.