TNS-12502: TNS listener received no CONNECT_DATA from client


Sometimes You can get “TNS-12502: TNS:listener received no CONNECT_DATA from client  ” error.


Details of error are as follows.

TNS-12502: TNS:listener received no CONNECT_DATA from client
Cause: No CONNECT_DATA was passed to the listener.
Action: Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor.

If you got this error,  it means your host definition in local_listener parameter is not correct, so fix it as follows.


Following description includes incorrect Host Definition as follows.


Fix and add the domain name and Correct Host Definition as follows.

(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = msdbadm01.domain.local) (PORT = 1521))))


Run the following commands one by one on Node 1 and Node2 if you are using RAC, if not you can change it according to Single Instance.

SQL> alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=msdbadm01.domain.local)(PORT=1521))))' scope=both sid='MSDB1';

SQL> alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=msdbadm02.domain.local)(PORT=1521))))' scope=both sid='MSDB2';

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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