ORA-06401: NETCMN: invalid driver designator tips Oracle Error Tips by Stephanie F.

 

The Oracle docs note this on the ora-06401 error:

ORA-06401 NETCMN: invalid driver designator
 

Cause: The login (connect) string contains an invalid driver designator.

 

Action: Correct the string and re-submit.

Internet sources contain information on error ORA-06401, specifically when using database links.  Here is the description of the ORA-06401 problem:

You have multiple servers running Oracle version 7.3.4.2 with one or more
databases on each one. You have several database links that were established and working prior to an upgrade. After upgrading and importing configuration files, the use of any database links on one server return an ORA-06401 error.
This is a confusing error because it relates to an incorrect SQL*Net version 1 connect string and there aren't any version 1 products installed.

Furthermore,  there is no real explanation in the actions related to ORA-06401, except for " it relates to SQL*Net client software on the server (front end database trying to connect to a second database using SQL*Net on behalf of a database link)." There is resolution to ORA-06401 however:

Solution Description:
=====================

If you ftp configuration files from a working client or server machine in
binary mode, the last character on each line is ^M. This is considered an
illegal character in a configuration file (similar to using a tab character
instead of indenting with blank spaces).

These ^M characters can be removed all at once by invoking the following
command in the Unix editor vi while still in command mode:

:%s/.$// <enter>

Solution Explanation:
=====================

SQL*Net parses the "tnsnames.ora" file for connection information. Seeing the first character of ^M after the alias somehow made SQL*Net think it had an invalid protocol selection for a version 1 connect string. This prompted the computer to return an invalid version 1 error, ORA-06401. Also for some reason, it only affected connection attempts using a database link.