VMS Help TCPIP Services, Programming Interfaces, RPC Client Routines, get_myaddr_dest, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 addr
    A pointer to a sockaddr_in structure that the routine will load
    with the local internet address which would provide a connection
    to the remote address specified in dest.
 dest
    A pointer to a sockaddr_in structure containing an internet
    address of a remote host.