Oracle Message ORA-16662 - network timeout when contacting a database

ERRORnetwork timeout when contacting a database
CAUSEIn response to the issued command, the Data Guard broker attempted to contact a database in the Data Guard configuration. That attempt failed because there was no response from that database after the period of time specified by the NetTimeout property for that database.
ACTIONCheck the Data Guard broker log for the details of the failure. Fix the problem and try the command again.