mtu was not the part of eigrp metric

[sarahr202]

Hi everybody1

i was reading a cisco press book by Wendell Odom. I was surprised to read the following:

" Past documents and books often stated that Eigrp and its predecssor,igrp also could use mtu as part of the metric,but mtu cannot be used and was never considered as part of the calculation"

I have one more question

Let say we have following route in eigrp routing table.

D 199.199.199.0/24[90/10] via 198.198.198.0 s0

we have the following feasible successor

199.199.199.0[90/20]via 197.197.197.0 s1

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Now if i use the variance 2, would the feasible successor be installed in routing table?

My book says any feasible routes with FD< variance*(FD of currently installed route in routing table), will be installed in routing table.

In our case Fd of feasible successor route is equal not less than 2*10.

where 2 is the variance

10 is Fd of currently installed route( successor route)

thanks a lot!

[viyuan700 · Accepted solution]

Now if i use the variance 2, would the feasible successor be installed in routing table?

No feasible successor will not be installed even though equal to 10*2.

Also, If for any route Feasible disatnce is less than variance* Feasible distance of successor, route will not be installed if reported distance is greater than the feasible distance for that particular route.