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With the default metric, traffic from RouterH to RouterJ goes out interface fe-1/0/0,<br />

which is one hop away:<br />

aviva@RouterJ> show route 192.168.18.1<br />

inet.0: 12 destinations, 12 routes (12 active, 0 holddown, 0 hidden)<br />

+ = Active Route, - = Last Active, * = Both<br />

192.168.18.1/32 *[OSPF/10] 00:26:19, metric 1<br />

> to 10.0.2.1 via fe-1/0/0.0<br />

Use the traceroute command to verify this:<br />

[edit protocols ospf area 0.0.0.0 interface fe-1/0/0.0]<br />

aviva@RouterJ# run traceroute 192.168.18.1<br />

traceroute to 192.168.18.1 (192.168.18.1), 30 hops max, 40 byte packets<br />

1 192.168.18.1 (192.168.18.1) 10.905 ms 9.060 ms 9.807 ms<br />

If you change the metric value on the fe-1/0/0 interface to 2, you create an equalcost<br />

path to RouterH:<br />

[edit protocols ospf area 0.0.0.0]<br />

aviva@RouterJ# show<br />

interface fe-1/0/1.0;<br />

interface fe-1/0/0.0 {<br />

metric 2;<br />

}<br />

The cost is 2, whether packets go through interface fe-1/0/0 or interface fe-1/0/1:<br />

[edit protocols ospf area 0.0.0.0]<br />

aviva@RouterJ# run show route 192.168.18.1<br />

inet.0: 12 destinations, 12 routes (12 active, 0 holddown, 0 hidden)<br />

+ = Active Route, - = Last Active, * = Both<br />

192.168.18.1/32 *[OSPF/10] 00:00:08, metric 2<br />

to 10.0.2.1 via fe-1/0/0.0<br />

> to 10.0.0.1 via fe-1/0/1.0<br />

Because we want traffic to always go through RouterG, we need to set the metric to<br />

something greater than 2, so in this recipe we set it to 3. The traffic now goes along<br />

the desired path:<br />

[edit protocols ospf area 0.0.0.0]<br />

aviva@RouterJ# run show route 192.168.18.1<br />

inet.0: 12 destinations, 12 routes (12 active, 0 holddown, 0 hidden)<br />

+ = Active Route, - = Last Active, * = Both<br />

192.168.18.1/32 *[OSPF/10] 00:00:06, metric 2<br />

> to 10.0.0.1 via fe-1/0/1.0<br />

The traceroute shows the path through interface 10.0.0.1 on RouterG:<br />

[edit protocols ospf area 0.0.0.0 interface fe-1/0/0.0]<br />

aviva@RouterJ# run traceroute 192.168.18.1<br />

traceroute to 192.168.18.1 (192.168.18.1), 30 hops max, 40 byte packets<br />

1 10.0.0.1 (10.0.0.1) 12.170 ms 8.826 ms 9.798 ms<br />

2 192.168.18.1 (192.168.18.1) 10.313 ms 15.829 ms 13.332 ms<br />

This is the Title of the Book, eMatter Edition<br />

Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.<br />

Adjusting OSPF Link Costs | 407

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