/FIXED_SERVER
    /NOFIXED_SERVER

    Specifies that the proxy server should fail to start if the
    server number specified by the /SERVER qualifier is not
    available. See /SERVER qualifier for more information about
    server numbers. This option is useful for starting standalone
    servers as detached processes. In this case, the proxy server has
    no method to return the selected server number. This option is
    ignored for managed proxy servers.

    The default is /NOFIXED_SERVER.