Comments on: Resolving Oracle Database ORA-12638 Error in Windows http://www.dbuggr.com/milly/resolving-oracle-database-ora-12638-error-windows/ Share Knowledge & Be Rewarded Fri, 03 Feb 2012 23:13:48 -0600 http://wordpress.org/?v=2.8.6 hourly 1 By: milly http://www.dbuggr.com/milly/resolving-oracle-database-ora-12638-error-windows/comment-page-1/#comment-1747 milly Fri, 15 Jan 2010 17:18:29 +0000 http://www.dbuggr.com/milly/resolving-oracle-database-ora-12638-error-windows/#comment-1747 It is possible that the OS user's password is changed. After rebooting the system, the Credential Failure message started to appear. There are two ways to resolve this: 1. Update the password again, and restart your Windows server again. 2. Replacing the line: <code>SQLNET.AUTHENTICATION_SERVICES= (NTS)</code> with <code>SQLNET.AUTHENTICATION_SERVICES= (NONE)</code>in sqlnet.ora can resolved the issue by disabling local support for authenticating using Windows credentials. The NTS (Network Telephony Services) makes the Oracle client attempt to use your current Windows domain credentials to authenticate you with the Oracle server. This could fail for a couple of reasons: - The Oracle server is not configured to support Windows authentication - The credentials you use to login to your local machine are not sufficient to allow you to login to the server. It is possible that the OS user’s password is changed. After rebooting the system, the Credential Failure message started to appear.

There are two ways to resolve this:
1. Update the password again, and restart your Windows server again.
2. Replacing the line:
SQLNET.AUTHENTICATION_SERVICES= (NTS) with
SQLNET.AUTHENTICATION_SERVICES= (NONE)in sqlnet.ora can resolved the issue by disabling local support for authenticating using Windows credentials.

The NTS (Network Telephony Services) makes the Oracle client attempt to use your current Windows domain credentials to authenticate you with the Oracle server. This could fail for a couple of reasons:

- The Oracle server is not configured to support Windows authentication
- The credentials you use to login to your local machine are not sufficient to allow you to login to the server.

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