Lab5 调整OSPF链路开销

爱卫生

通过调整OSPF链路开销，可以达到引导数据流量的目的。

本练习的目标是：

1）了解怎样通过配置命令调整OSPF的链路cost值来达到重定向流量到其他链路的目的。

2）使用show命令进行相关验证。

附件包含拓扑、步骤及指令、验证三部分。

本实验通过Juniper模拟器实现，所有接口名称均为em开头。如果是实际设备请将此接口名称进行替换。

拓扑图如下：

部分内容摘要如下：

Adjusting OSPF Link Costs Configuration Overview

Adjusting OSPF link cost could redirect the traffic between the multiple paths. It always used in migration or software upgrade scenario.

Part Three: Adjusting OSPF Link Cost

From the traceroute result shown above, we can found the route between 1.1.1.1 and 3.3.3.3 are go through the primary path (R1-R2-R3) for it have the lowest metric 2 to destination than the secondary path, the default metric for fast Ethernet interface is 1, thus the routes traverse 2 FE links , so the total cost is 1+1=2, likewise, the metric for secondary path is 3.

Now, the next step is adjusting link cost , so the traffic will be redirect to secondary path. We could change the link metric between the R2 and R3 to a bigger value, the traffic will then redirect.

Using the following script to adjusting the cost.

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lab@aaa# show | display set | match metric
set logical-routers R2 protocols ospf area 0.0.0.0 interface em0.23 metric 100
set logical-routers R3 protocols ospf area 0.0.0.0 interface em1.23 metric 100
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