How to fix the Oracle error TNS-00123: Unable to perform a listen on configured ADDRESS(es)?

In this post, you’ll learn more about the Oracle ErrorTNS-00123: Unable to perform a listen on configured ADDRESS(es) with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

TNS-00123: Unable to perform a listen on configured ADDRESS(es)

Reason for the Error TNS-00123: Unable to perform a listen on configured ADDRESS(es)

Cause: Another process is already listening on this address or the ADDRESS is incorrectly defined.

How to fix the Error TNS-00123: Unable to perform a listen on configured ADDRESS(es) ?

You can fix this error in Oracle by following the below steps

Action: Check the ADDRESS(es) defined in TNSNET.ORA (for the Connection Manager) for errors. Verify that another program is not using them.