Junos OS

Hi people,

I am new to Junos. I want to test out a simple Junos-ES setup, but it doesn' work like I want. I try to build a very simple router config without Nat. Here is this config.

version 9.2R1.10;
system {
    host-name gw01;
    domain-name my.local;
    root-authentication {
        encrypted-password "$1$55NlTuP4$Mxiph57KFUL4bZlBHrm9V/";
    }
    services {
        ssh;
        telnet;
        web-management {
            http;
        }
    }
    syslog {
        user * {
            any emergency;
        }
        file messages {
            any any;
            authorization info;
        }
        file interactive-commands {
            interactive-commands any;
        }
    }
    license {
        autoupdate {
            url https://ae1.juniper.net/junos/key_retrieval;
        }
    }
}
interfaces {
    ge-0/0/0 {
        unit 0 {
            description INTERNAL;
            family inet {
                address 172.17.1.1/24;
            }
        }
    }
    ge-0/0/1 {
        unit 0 {
            description EXTERNAL;
            family inet {
                address 192.168.1.2/24;
            }
        }
    }
    lo0 {
        unit 0 {
            family inet {
                address 127.0.0.1/32;
            }
        }
    }
}
routing-options {
    static {
        route 0.0.0.0/0 next-hop 192.168.1.1;
    }
}
security {
    zones {
        security-zone trust {
            tcp-rst;
            interfaces {
                ge-0/0/0.0 {
                    host-inbound-traffic {
                        system-services {
                            all;
                        }
                    }
                }
            }
        }
        security-zone untrust {
            interfaces {
                ge-0/0/1.0 {
                    host-inbound-traffic {
                        system-services {
                            all;
                        }
                    }
                }
            }
        }
    }
    policies {
        from-zone trust to-zone trust {
            policy default-permit {
                match {
                    source-address any;
                    destination-address any;
                    application any;
                }
                then {
                    permit;
                }
            }
        }
        from-zone trust to-zone untrust {
            policy default-permit {
                match {
                    source-address any;
                    destination-address any;
                    application any;
                }
                then {
                    permit;
                }
            }
        }
        from-zone untrust to-zone trust {
            policy default-deny {
                match {
                    source-address any;
                    destination-address any;
                    application any;
                }
                then {
                    permit;
                }
            }
        }
        default-policy {
            deny-all;
        }
    }
}

I have successful ping to external interface 192.168.1.2 from the local host (ip=172.17.1.2), but next hop ping to 192.168.1.1 does not work.

When I make a little changes in this config to setup a simple source interface Nat, it seems all work good. In this case I can ping 192.168.1.1 and even connect to http server on it.

<...>
        from-zone trust to-zone untrust{
            policy Int2Ext {
                match {
                    source-address any;
                    destination-address any;
                    application any;
                }
                then {
                    permit {
                        source-nat {
                            interface;
                        }
                    }
                }
            }
        }
<...>

I don't understand why a first config does not work. It make me crazy

Can you please check my config, if there is a misktake I doesn't see.

Hello there,

Config seems pretty basic to me.

Does your system at 192.168.1.1 have a route back to 172.17.1.2?

With src NAT, all traffic sent from 172.17.1.2 to 192.168.1.1 gets its src.IP NAT-ed to 192.168.1.2 and of course, your system at 192.168.1.1 knows how to route to its connected subnet.

Rgds

Alex

Thanks to Alex, I have review my test network config with more accuracy. This junos config is correct!

It seems a problem was somewhere in PC's host firewall + test virtual machine options.

Thank you once more!