Message Oracle NNC-00419 - authoritative server is unreachable

ERRORauthoritative server is unreachable
CAUSEA name server request cannot be processed because the server which received the operation does not own the name specified in the request and cannot locate the server which does own the name. The error is almost always transient, and occurs either because the path between the server receiving the request and the requests final destination has been interrupted, or because the final destination is down.
ACTIONNot normally visible to the user, except when using the name server control program. Because the error is typically a transient one, retrying the failing operation will usually work. If the failure persists, the name server which is allowed to process the failing operation is probably shut down or unreachable. Contact your name server administrator to make sure that your sites name servers are running, and are properly configured.