VMS Help TCPIP Services, Programming Interfaces, Sockets API, gethostbyname(), Errors  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    ENETDOWN           TCP/IP Services was not started.
    HOST_NOT_FOUND     Host is unknown.
    NO_DATA            The server recognized the request and the
                       name, but no address is available for the
                       name. Another type of name server request may
                       be successful.
    NO_RECOVERY        An unexpected server failure occurred. This is
                       a nonrecoverable error.
    TRY_AGAIN          A transient error occurred, for example,
                       the server did not respond. A retry may be
                       successful.