Dataguard returns ORA-16664: UNABLE TO RECEIVE THE RESULT FROM A DATABASE

After succesfully creating a standby database using RMAN duplicate on a primairy site 11.1.0.6 .
The logfle shipping works ok, but the dg_broker seems to have a problem which i couldn’t pin down.
The Dataguard broker was configured using Enterprise Grid Control using the add standby database option “Manage
existing standby database”. The configuration steps were preformed successfully, however this error is shown for the standby database.

The Data Guard status of stby is Error ORA-16664: unable to receive the result from a database.

Searching this error reveals that there might be a network error.

ORA-16664: unable to receive the result from a database
Cause: During execution of a command, a database in the Data Guard broker configuration failed to return a result.
Action: Check Data Guard broker logs for the details of the failure. Fix any possible network problems and try the command again.

As the RMAN duplicatie is done over TNS using the following command
“rman target sys/xxx@prod AUXILIARY sys/xxx@stby” . I would say that the network setting for TNS are
correct, so what does this error actually mean ?

In the background i could find serveral Dataguard logfiles showing me mixed errors on the subject.

Primary site DG log shows :

….
DG 2009-05-19-08:48:27 1012000 4 686031872 DMON: CTL_GET_STATUS operation completed
DG 2009-05-19-08:48:45 0 2 0 NSV1: Received error ORA-16664 from target remote site stby.
DG 2009-05-19-08:48:45 0 2 686031873 DMON: Database stby returned ORA-16664

Standby site DG log shows :


DG 2009-05-19-08:51:00 0 2 686031879 Operation CTL_GET_STATUS continuing with warning, status = ORA-16809
DG 2009-05-19-08:51:00 0 2 0 NSV0: Failed to connect to remote database prod. Error is ORA-00604
DG 2009-05-19-08:51:00 0 2 0 NSV0: Failed to send message to site prod.
Error code is ORA-00604.
DG 2009-05-19-08:51:00 0 2 0 DMON: Database prod returned ORA-00604

The Data Guard Command-Line Interface ( DGMGRL ) showed the following error.

DGMGRL> show configuration

Configuration
Name: prod
Enabled: YES
Protection Mode: MaxPerformance
Databases:
prod – Primary database
stby – Physical standby database

Fast-Start Failover: DISABLED

Current status for “prod”:
Warning: ORA-16607: one or more databases have failed

All these errors seem very surfear but at the end it all came down to a faulty “logon trigger” which was implemented by another Database Administrator.
As normal connections worked this was not the first thing you would come to , but at the end by dropping this faulty trigger the problem was solved !