TNS-12599: TNS:cryptographic checksum mismatch

Symptoms:
After Enterprise manager Grid Control 12c installed, following message appears in alert log of repository database.


Fri Dec 09 14:11:21 2011


***********************************************************************

NI cryptographic checksum mismatch error: 12599.

VERSION INFORMATION:
TNS for Linux: Version 11.2.0.2.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.2.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.2.0 - Production
Time: 09-DEC-2011 14:11:21
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
Fri Dec 09 14:19:45 2011

Cause:
This is due to Bug 9871805. The Enterprise Manager OMS connects to the 11gR1 and 11gR2 Repository database
using 10.2 JDBC Thin connection and AES256 encryption algorithm.
The 11gR1 and 11gR2 database does not support client JDBC connections using AES encryption, hence the TNS-
12599: TNS:cryptographic checksum mismatch

Solution:
To Workaround the issue please do the following:
On Repository database side, set the parameter
SQLNET.ENCRYPTION_TYPES_SERVER= (3DES168)
in sqlnet.ora file