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11g and Newer: ORA-609 TNS-12537 and TNS-12547 or TNS-12170 in DB Alert.log (Doc ID 1116960.1)

Last updated on APRIL 26, 2023

Applies to:

Oracle Net Services - Version and later
Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.
The issue documented here is limited in scope to 11g and newer releases.


The following errors are intermittently posted to the alert.log of a database instance that is at or newer than 11gR1. All releases that are newer than 11g would be affected.


This might be a new installation of the database.   The ORA-609 error code was introduced in 11g.  Also introduced in 11g is the ADR diagnostic method which results in TNS errors such as this to be thrown in the alert versus the sqlnet.log. 
If this database has been in operation for a while, it is possible this error has arisen when an increase in the number of connections or workload has increased.


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