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

    This function finds the first network record in the networks
    database with the given address.
    The getnetbyaddr() and getnetbyname()  functions use a common
    static area for their return values. Subsequent calls to any of
    these functions overwrite any previously returned network entry.
    You must make a copy of the network entry if you want to save it.