Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 








ORA-12518: TNS: listener could not hand off client connection tips

Oracle Error Tips by Burleson Consulting

Note:  Starting in 11gR2, the listener log is not activated by default.  You have to turn on listener logging:   logging_listener_name=on

Oracle docs note this about ORA-12518:

ORA-12518: TNS:listener could not hand off client connection
Cause: The process of handing off a client connection to another process failed.

Action: Turn on listener tracing and re-execute the operation. Verify that the listener and database instance are properly configured for direct handoff. If problem persists, call Oracle Support.

ORA-12518 has been known to occur in Oracle Net Services version in which attempting new connections on the database throw either ORA-12518 or TNS-12518. 

The ORA-12518 appears in the listener log upon new user connection.  Also, check out these MOSC Notes:

- ORA-12518 / TNS-12518 Troubleshooting [ID 556428.1]

- TROUBLESHOOTING GUIDE TNS-12518 TNS listener could not hand off client connection [ID 550859.1]



Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2017

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.

Remote Emergency Support provided by Conversational



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster