Re: EIGRP Traffic Share Count

Hi Bilal,

You want to read this post-
http://blog.ine.com/2009/05/01/understanding-unequal-cost-load-balancing/..
This has an explanation on the traffic share ratio you are seeing above.

<http://blog.ine.com/2009/05/01/understanding-unequal-cost-load-balancing/>I
think the answer you seek though is

EIGRP will divide each links metric by the largest paths metric..

3584 / 3072 which is 1.166
3584 / 3584 which is 1

FYI- 120 / 103 = 1.165

EIGRP will round down to the nearest integer so the first path is actually
"1"

I also believe the largest metric would have be a path being selected by
EIGRP for placement into the routing table.. If your route is not selected
because the metric is larger than the
 Variance x feasible distance.. I do not believe it will be included in the
route traffic share calculation.

HTH

Garth

On Sun, Sep 26, 2010 at 6:14 PM, Bilal Hansrod <bilal.hansrod_at_gmail.com>wrote:

> Hello Everyone,
>
> I am having difficulty calculating the EIGRP Traffic Share Count. As far as
> my understanding regarding Traffic Share Count is, you divide the largest
> metric with lowest to forward packets based on number. For example
>
> A-X = Metric is 10
> B-X = Metric is 20
> C-X = Metric is 30
> D-X = Metric is 40
> E-X = Metric is 90
>
> If I configure variance 4, it means all above metric will be used for load
> balancing except E-X (90), because it does not fall under 80 (Lowest Metric
> X 4). So when calculate, I still use E-X Metric for Traffic Share Count.
>
>
> A-X = Metric is 10 = Traffic Share Count (90/10) = 9
> B-X = Metric is 20 = Traffic Share Count (90/20) = 5
> C-X = Metric is 30 = Traffic Share Count (90/30) = 3
> D-X = Metric is 40 = Traffic Share Count (90/40) = 2
>
> It means 9 packets will be sent via A-X, 5 packets via B-X, 3 packets via
> C-X, and 2 packets via D-X and round robin. Am I correct till here??
>
> Now, when I have below output, how is Traffic Share Count calculated
>
> Rack1R6#show ip route 155.1.9.9
> Routing entry for 155.1.9.0/24
> Known via "eigrp 100", distance 90, metric 3072, type internal
> Redistributing via eigrp 10, eigrp 100
> Advertised by eigrp 10
> Last update from 155.1.146.1 on FastEthernet0/0.146, 00:01:04 ago
> Routing Descriptor Blocks:
> 155.1.146.1, from 155.1.146.1, 00:01:04 ago, via FastEthernet0/0.146
> Route metric is 3584, traffic share count is 103
> Total delay is 140 microseconds, minimum bandwidth is 1544 Kbit
> Reliability 255/255, minimum MTU 1500 bytes
> Loading 1/255, Hops 4
>
> * 155.1.67.7, from 155.1.67.7, 00:01:04 ago, via FastEthernet0/0.67
> Route metric is 3072, traffic share count is 120
> Total delay is 120 microseconds, minimum bandwidth is 100000 Kbit
> Reliability 255/255, minimum MTU 1500 bytes
> Loading 1/255, Hops 2
>
>
> Anyone's help will be highly appreciated,
>
> Regards,
>
> Bilal
>
>
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Received on Sun Sep 26 2010 - 20:29:44 ART