Port Address Translation with MS-DPC || j-nsp mailing list thread: https://puck.nether.net/pipermail/juniper-nsp/2026-April/039361.html

napt-44.conf

root@lab-mx960> show configuration services
service-set pat-service-set {
    nat-rules rule-napt-44;
    interface-service {
        /* first PIC of MS-DPC in slot 9; Multiservices MIC should use "ms" interface instead of "sp" interface  */
        service-interface sp-9/0/0;
    }
}
nat {
    pool napt-pool {
        address 10.1.1.1/32;
        port {
            automatic {
                random-allocation;
            }
        }
    }
    rule rule-napt-44 {
        match-direction output;
        /* such simple conf will also punt the L3VPN BGP session traffic to multiservices line-card */
        term match-all {
            then {
                translated {
                    source-pool napt-pool;
                    translation-type {
                        napt-44;
                    }
                }
            }
        }
    }
}

root@lab-mx960>

root@lab-mx960> show configuration interfaces
ge-2/1/6 {
    description L3VPN;
    unit 0 {
        family inet {
            service {
                input {
                    service-set pat-service-set;
                }
                output {
                    service-set pat-service-set;
                }
            }
            address 10.1.1.1/31;
        }
    }
}
ge-2/1/8 {
    description LAN;
    unit 0 {
        family inet {
            address 10.4.4.1/24;
        }
    }
}
sp-9/0/0 {
    unit 0 {
        family inet;
    }
}
fxp0 {
    unit 0 {
        family inet {
            dhcp;
        }
    }
}

root@lab-mx960>