TNS-12599: TNS:cryptographic checksum mismatch

Have your alert logs been littered with TNS-12599 errors, after upgrading to OEM 11g? These errors started appearing in the alert logs on OEM repository database, and the monitored databases.

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NI cryptographic checksum mismatch error: 12599.

VERSION INFORMATION:

TNS for Solaris: Version 11.2.0.1.0 – Production

Oracle Bequeath NT Protocol Adapter for Solaris: Version 11.2.0.1.0 – Production

TCP/IP NT Protocol Adapter for Solaris: Version 11.2.0.1.0 – Production

Time: 24-MAR-2011 17:34:35

Tracing not turned on.

Tns error struct:

ns main err code: 12599

TNS-12599: TNS:cryptographic checksum mismatch

ns secondary err code: 2526

nt main err code: 0

nt secondary err code: 0

nt OS err code: 0

Thu Mar 24 18:24:51 2011

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This is due to bug 9844654.  There is an easy workaround.  Modify the $ORACLE_HOME/network/admin/sqlnet.ora of each server involved, and add the following line:

SQLNET.ENCRYPTION_TYPES_SERVER= (3DES168)

Then restart the listeners involved.