TNS-12168
        Cannot connect to database. LDAP LDAP_operation failed
        - LDAP_operation: The LDAP operation which has failed.
        Cause
        A connection to a database or other service was requested using LDAP directory naming method but it could not be resolved because of LDAP initialization failure or connection to LDAP directory server failure.
        Action
        The message indicates whether there was a LDAP initialization failure, connect failure, auth failure, or permission failure.
- Check for mistakes in the LDAP configuration that you used.
- Make sure the directory_servers specified is correct.
- Verify that the LDAP directory server is up and that it is accessible.
- Make sure the read/write permissions exist for OracleContext Object and its subtree.
        
     
    
    
        TNS-12168
        TNS:Unable to contact LDAP Directory Server
        
        
        Cause
        Cannot contact LDAP directory server to get Oracle Net configuration.
        Action
        Verify that the directory server is up and accessible from the network. Verify that directory access configuration is correct.  For more information see the Oracle Internet Directory Administrators Guide or the Oracle Net Administrators Guide.
        
     
    
    
        TNS-12168
        TNS:Unable to contact LDAP Directory Server
        
        
        Cause
        Cannot contact LDAP directory server to get Oracle Net configuration.
        Action
        Verify that the directory server is up and accessible from the network. Verify that directory access configuration is correct.  For more information see the Oracle Internet Directory Administrators Guide or the Oracle Net Administrators Guide.