From: George Hansen (HansenG@xxxxxxxxxxxxxxxx)
Date: Wed Mar 20 2002 - 15:06:53 GMT-3
If k5 equals 0, the composite IGRP or Enhanced IGRP metric is computed accordin
g to the following formula:
metric = [k1 * bandwidth + (k2 * bandwidth)/(256 - load) + k3 * delay]
If k5 does not equal zero, an additional operation is done:
metric = metric * [k5 / (reliability + k4)]
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/np1_r/1r
prt1/1reigrp.htm
>>> "Rising, Danny" <danny.rising@wachovia.com> 03/20/02 08:39AM >>>
> These facts are given...
>
> To determine EIGRP metric the following formula is used.
>
> metric = [K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay] *
> [K5 / (reliability + K4)]
>
> Default values are as follows...
>
> K1 = 1
> K2 = 0
> K3 = 1
> K4 = 0
> K5 = 0
>
> Capmark uses
>
> K1 = 0
> K2 = 1
> K3 = 1
> K4 = 1
> K5 = 0
> K6= 0
>
> In both cases, K5 is equal to 0. 0 divided by anything is zero and 0
> multiplied by anything is zero. So regardless of other values, if K5=0
> then metric=0. Cisco says this in the white paper on EIGRP
>
> For default behavior, you can simplify the formula as follows:
>
> metric = bandwidth + delay
>
> Combine this formula with the scaling factors and you have:
>
> [(10^7/min bandwidth) + sum of delays] * 256
>
> Just how in the heck do they get metric = BW + Delay if the "reliability
> modifier" is always 0?
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