We have some 19c Standard Edition (Version 19.18) Databases running on Windows Servers and several database links between them, which are used by database jobs for communication between different applications. Recently we had a problem, that the communication via the database links failed while one our two AD-Servers was down. Both AD-Servers also work as DNS Servers. In the ALERT.LOG of the affected Oracle-Servers was written:
Fatal NI connect error 12638, connecting to: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=...(CID=(PROGRAM=d:\app\oracle\product\19c\dbhome\bin\ORACLE.EXE)(HOST=ORA4PROD)(USER=OracleServiceORA4PCDB))))
TNS-12638: Credential retrieval failed
In the SQLNET.ORA we have the settings:
SQLNET.AUTHENTICATION_SERVICES = (NTS)
SQLNET.NO_NTLM = FALSE
Our impression is, that there is a problem when switching from the main AD/DNS-Server to the second server. Is there any configuration to be done to solve this problem?