security {
    nat {
        source {
            rule-set nat-rule {
                from zone trust;
                to zone untrust;
                rule source-nat {
                    match {
                        source-address 0.0.0.0/0;
                    }
                    then {
                        source-nat {
                            interface;
                        }
                    }
                }
            }
        }
        destination {
            pool A {
                address 192.168.0.20/32 port 22;
            }
            rule-set RS2 {
                from zone untrust;
                rule DA2 {
                    match {
                        destination-address 213.103.x.x/24;
                        destination-port 22;
                    }
                    then {
                        destination-nat pool A;
                    }
                }
            }
        }
    }
    zones {
        security-zone trust {
            interfaces {
                vlan.0 {
                    host-inbound-traffic {
                        system-services {
                            all;
                        }
                    }
                }
            }
        }
        security-zone untrust {
            host-inbound-traffic {
                system-services {
                    ssh;
                }
            }
            interfaces {
                fe-0/0/0.0 {
                    host-inbound-traffic {
                        system-services {
                            dhcp;
                        }
                    }
                }
            }
        }
    }
    policies {
        from-zone trust to-zone untrust {
            policy internet-access {
                match {
                    source-address any;
                    destination-address any;
                    application any;
                }
                then {
                    permit;
                }
            }
        }
    }
}