VMS Help TCPIP Services, Programming Interfaces, RPC Portmapper Routines, pmap_getmaps_#, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    A client interface to the Portmapper, which returns a list of the
    current ONC RPC program-to-port mappings on the host located at
    the internet address addr. The SHOW PORTMAPPER management command
    uses this routine.