使用juniper SRX 配置双链路PPPoE实现冗余功能

这实验是本人家里的真实环境，由于当时己经有一条在用的电信宽带，且移动当时推送一条可以免费使用一年的家庭宽带正好可以用上，后来一年到期后就再也没使用了。。

有时候为了节省开支，又想实现链路冗余，可以上网淘一台二手设备来试试。本环境适用于小型企业或者家庭。

拓扑如下：

SRX配置：

---------------------------------接口配置--------------------------------
interfaces {
    fe-0/0/2 {
        unit 0 {                        
            family inet {
                address 10.1.1.1/24;
            }
        }
    }
    fe-0/0/4 {
        unit 0 {
            encapsulation ppp-over-ether;
        }
    }
    fe-0/0/5 {
        unit 0 {
            encapsulation ppp-over-ether;
        }
    }
    pp0 {
        unit 0 {
            ppp-options {
                pap {
                    local-name "电信账号";
                    local-password "电信账号密码"; ## SECRET-DATA
                    passive;
                }
            }
            pppoe-options {
                underlying-interface fe-0/0/4.0;
                idle-timeout 0;
                auto-reconnect 3;
                client;
            }
            family inet {
                mtu 1492;
                negotiate-address;
            }
        }   
        unit 1 {
            ppp-options {
                pap {
                    local-name "移动账号";
                    local-password "移动账号密码"; ## SECRET-DATA
                    passive;
                }
            }
            pppoe-options {
                underlying-interface fe-0/0/5.0;
                idle-timeout 0;
                auto-reconnect 3;
                client;
            }
            family inet {
                mtu 1492;
                negotiate-address;
            }
        }
    }
---------------------------------路由配置--------------------------------
routing-options {
    static {
        route 0.0.0.0/0 {
            next-hop pp0.0;
            qualified-next-hop pp0.1;
   　　　　　　　　preference 10;
        }
        preference 5;
    }
    forwarding-table {
        export load-balance;
    }
}
policy-options {
    policy-statement load-balance {
        then {
            load-balance per-packet;
        }                               
    }
}
---------------------------------NAT配置--------------------------------
security {    
    nat {
        source {
            rule-set trust-to-untrust {
                from zone trust;
                to zone untrust;
                rule source-nat {
                    match {
                        source-address 0.0.0.0/0;
                    }
                    then {
                        source-nat {
                            interface;
                        }
                    }
                }
            }
---------------------------------策略配置--------------------------------
    policies {
        from-zone trust to-zone untrust {
            policy Permit_Any {
                match {
                    source-address any;     
                    destination-address any;
                    application any;
                }
                then {
                    permit;
                    log {
                        session-init;
                    }
                }
            }
---------------------------------区域配置--------------------------------
    zones {
        security-zone trust {
            host-inbound-traffic {
                system-services {
                    all;
                }
                protocols {
                    all;
                }
            }
            interfaces {
                fe-0/0/2.0;
            }
        }                               
        security-zone untrust {
            screen Untrust;
            host-inbound-traffic {
                system-services {
                    all;
                }
                protocols {
                    all;
                }
            }
            interfaces {
                pp0.0;
                pp0.1;
            }
        }
    }

有几点需要注意的：

1.PPPoE链路中，MTU最大为1492 Bytes

2.无线路由器只是作为中继，或者DHCP服务器，拔号是在SRX上进行拨号