All Oracle Error CodesOracle DBA Forum

NNC-00419:

authoritative server is unreachable
Cause: A 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 request's final destination has been interrupted, or because the final destination is down.
Action: Not 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 site's name servers are running, and are properly configured.