Confusion!!!! Need your urgent HELP Please

Unanswered Question
May 7th, 2008
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I am reading CCNA ICND2 640-816 book of Wendol Odom,

I find a mistake here, please help me,

The Author First Says:

OSPF chooses the least-cost route between the router and a subnet by adding up the

outgoing interfaces' OSPF costs. Each interface has an OSPF cost associated with it. The

router looks at each possible route, adds up the costs on the interfaces out which packets

would be forwarded on that route, and then picks the least-cost route


An Example

Route R4 - R1 - R5 : cost 1 + 100 + 10 = 111

Route R4 - R2 - R5 : cost 1 + 64 + 10 = 75

and then he says

If you add up the cost associated with each interface, the first of the two routes totals a cost

of 111, and the second totals 75. So, R4 adds the route through R1 as the best route and lists

R1's IP address as the next-hop IP address.

Please confirm, whether it is a mistake or really OSPF choose its best route based on least cost route,

In this case the route should be from R4 to R2 then R5

Please advise



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junshah22 Thu, 05/08/2008 - 01:01
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can I get the same presentation for EIGRP Please

Please send me its link,,




jrensink78 Thu, 05/08/2008 - 06:41
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Within any routing protocol, it will determine the best path based upon the lowest metric. Different routing protocols use different metric criteria. In OSPF, the interface cost is used. The lowest cost determines the best route. So in your example, the path through R2 is the best path for R4 to take.


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