juniper 交換機實施策略路由

本人第一次寫Blog，前端時間一直在研究juniper的策略路由，如今將相關配置分享下。

Juniper交換機的策略路由器，與cisco、H3C的邏輯原理不太同樣。

SRX支持原生的RPM觸發路由倒換，相似Cisco IP SLA的功能。M/T/MX/EX/QFX沒有這個功能，但可經過JUNOS內置的"event-options"這個通用的自動運維特性實現同樣的效果。

其原理是經過RPM監控目標地址，當監控失敗後RPM會在系統日誌裏生成"PING_TEST_FAILED」日誌，可在event-options裏定義"PING_TEST_FAILED"這一事件觸發後續動做，後續動做定義爲設備配置更改"change-configuration", 內容爲刪除原有靜態路由，生成新路由，而後deactive自身這條policy，active新的policy以在後面當監控目標成功後從新恢復原配置。

注意級別必須在Info級別如下才能看見RPM Trap信息

# show system syslog

user * {

any emergency;

}

file messages {

any notice;

authorization info;

}




配置RPM：

# show services

rpm {

     probe my-probe {

         test my-test {

             probe-type icmp-ping;

             target address 192.168.5.4;

             probe-count 3;

             probe-interval 1;

             test-interval 1;

             thresholds {

                 successive-loss 3;

             }

             traps test-failure;

         }

     }

}




配置event-options:

policy ping-fail {

     events PING_TEST_FAILED;

     attributes-match {

         PING_TEST_FAILED.test-owner matches my-probe;

         PING_TEST_FAILED.test-name matches my-test;

     }

     then {

         change-configuration {

             commands {

                 "delete routing-options static route 23.1.1.0/24 next-hop 12.1.1.2";

                 "set routing-options static route 23.1.1.0/24 next-hop 12.1.1.3";

                 "deactivate event-options policy ping-fail";

                 "activate event-options policy ping-success";

             }

             user-name lab;

             commit-options {

                 log "ping fail change is succeful!";

             }

         }

     }

}

inactive: policy ping-success {

     events PING_TEST_COMPLETED;

     attributes-match {

         PING_TEST_COMPLETED.test-name matches my-test;

         PING_TEST_COMPLETED.test-owner matches my-probe;

     }

     then {

         change-configuration {

             commands {

                 "set routing-options static route 23.1.1.0/24 next-hop 12.1.1.2";

                 "delete routing-options static route 23.1.1.0/24 next-hop 12.1.1.3";

                 "deactivate event-options policy ping-success";

                 "activate event-options policy ping-fail";

             }

             user-name lab;

             commit-options {           

                 log "ping ok change is succeful!";

             }

         }

     }

}