ORA-03135: connection lost contact

Sometimes You can get ” ORA-03135: connection lost contact ” error.


ORA-03135: connection lost contact

Details of error are as follows.

ORA-03135: connection lost contact

Cause: 1) Server unexpectedly terminated or was forced to terminate. 2) Server timed out the connection.

Action: 1) Check if the server session was terminated. 2) Check if the timeout parameters are set properly in sqlnet.ora.



If you got this error from Oracle clients like TOAD, SQL Developer, PL-SQL Developer or Applications, this ORA-03135 error is related with Network issues, so you need to check and fix your Network or VPN problems.





To resolve ORA-03135 error, you should increase the value of the expire_time parameter in the SQLNET.ORA file ( under $ORACLE_HOME/network/admin/ ) .


Add the following parameter to the SQLNET.ORA file



Set the parameters sqlnet.inbound_connect_timeout and inbound_connect_timeout_listenername to 0 to solve the ORA-03135.






Do you want to learn Oracle Database for Beginners, then Click and read the following articles.

Oracle Database Tutorials for Beginners ( Junior Oracle DBA )

About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

Leave a Reply

Your email address will not be published. Required fields are marked *