請問　ipfilter 要如何安裝[5]

                                  stop)
                                    echo "De-activating IP Forwarding..."
                                    /usr/sbin/ndd -set /dev/tcp ip_forwarding 0
                                    ;;
                                  *)
                                    echo "Usage: $0 (start|stop)" >&2
                                    exit 1
                                    ;;
                               esac
                               exit 0
                               
                 Make it executable
                          # chmod 744 /etc/init.d/ipforward

                 Then link it as /etc/rc2.d/S69ipforward
                          # ln -s /etc/init.d/ipforward /etc/rc2.d/S69ipforward
               
                 Note: ipforwarding must run after ipf & inet 

            (v) ipf and nat rules set:
                   Create a file called /etc/opt/ipf/ipnat.conf.  
                   /etc/opt/ipf/ipf.conf is already exist and is empty.

                   The file /etc/opt/ipf/ipf.conf is used to write your 
                   firewall rules, which is beyond the scope of this document.
                   Check the IP Filter HOWTO page for more info: 
                   http://unixcircle.com/ipf 

   (4) Installing OpenSSH (optional)