ORA-12170: TNS: Connect timeout occurred

Sometimes You can get “ORA-12170: TNS: Connect timeout occurred ” error.

ORA-12170: TNS:Connect timeout occurred

Details of error are as follows.

ORA-12170: TNS:Connect timeout occurred

Cause: The server shut down because connection establishment or communication with a client 
failed to complete within the allotted time interval. This may be a result of network or
 system delays; or this may indicate that a malicious client is trying to cause a 
Denial of Service attack on the server.

Action: If the error occurred because of a slow network or system, reconfigure one or all
in sqlnet.ora to larger values. If a malicious client is suspected, use the address in 
sqlnet.log to identify the source and restrict access. Note that logged addresses may not
 be reliable as they can be forged (e.g. in TCP/IP).

To solve this error, add the following parameters to the sqlnet.ora file under $ORACLE_HOME/network/admin.



And Check /etc/hosts file if it has DNS entry or not.


Do you want to learn more details about RMAN, then read the following articles.



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.

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