ORA-12638 Credential retrieval failed and ORA-01031: insufficient privileges

in sqlnet.ora file:

when i have SQLNET.AUTHENTICATION_SERVICES= (NTS)

i can't connect by PL/SQL developer arises "ORA-12638 Credential retrieval f开发者_JS百科ailed" ,but can connect by command line

when i have SQLNET.AUTHENTICATION_SERVICES= (NONE)

i can't connect

>sqlplus / as sysdba

arises "ORA-01031: insufficient privileges"

,but can connect by PL/SQL developer and command line when i supply username and password

I was facing the exact same issue.

When I made the change to SQLNET.AUTHENTICATION_SERVICES= (NONE) to resolve the ORA-12638 Credential retrieval failed.

I was then unable to connect with the sysdba privilege.

ORA-01031: insufficient privileges when sqlplus / as sysdba

The Solution:

I was able to find out, I could still connect as sysdba with the following command:

From within sqlplus:

connect sys as sysdba

From command line:

sqlplus sys as sysdba

In both cases, you will be prompted for your password. The password will be the same as your password that you setup for the SYSTEM user during the windows Oracle install.

Now you are connected with the sysdba rights you were trying to get with sqlplus / as sysdba.

The server administrator may not have setup NTS authentication on the database. You can't simply ask for your credentials to be authenticated by NTS in your client SQLNET.ORA file without agreement on the server side.