From 2.5.915 TPAM can query on DNS SRV records.
For Windows® Active Directory® systems, added ability for TPAM to query DNS for the SRV records of the domain controllers associated with the DNS name of the Active Directory domain populated in the network address box.
To do this enter the domain name in the "Network Address" on the Details | Information tab. This must match the domain entered on the "Domain Name" on the Connection tab. When performing a "Test System", "Reset Password" or "Check Password" the debug will show the IP of the domain controller was used "Using Domain Controller at address: x.x.x.x"