06-15-2009 08:35 PM - edited 03-04-2019 05:08 AM
Hi, I have Router R1, R2 & R3. Router R2 has Network 10.10.10.0/24. All are in Eigrp domain. From R1, we have two path to reach reach 10.10.10.x subnet. R1->R2 (Directly) & R1->R3->R2. I have to share data on 5:1 ratio, how we can do it.
R1(S0/0->256kbs)-> R2 (S0/0->256kbs)
R1(S0/1->1.536Mbs)-> R3(S0/0->1.536Mbs)
R3 (S0/1->1.28Mbs)-> R2(S0/1->1.28Mbs)
06-15-2009 11:14 PM
Hello Rupesh,
EIGRP metric with default K values is proportional to the sum of delays (in tens of microseconds 1 msec = 100 tens of microseconds) and to the inverse of the lowest BW in path expressed in kbps.
path1 = 256 * (Delay of s0/0 in tens of microseconds) + 256 * 10^7/256
path2 = 256 * (Delay_R1_s0/1+ Delay_R3_s0/1) + 256 * (10^7 / 1280)
lowest BW on path 2 is 1280 kbps.
you can get the delay parameters from
sh int serx/y on the routers.
The best path is path2, path1 provides a feasible successor so you can use the variance command
R1:
router eigrp xx
variance 6
you may need to tune the interface parameters delay and BW to get a 5:1 ratio between the two metrics.
Hope to help
Giuseppe
06-16-2009 01:51 AM
Now I have two qn-
1. Ration is 5:1, so Variance will 5 or 6
2.path2 = 256 * (Delay_R1_s0/1+ Delay_R3_s0/1) + 256 * (10^7 / 1280)
lowest BW on path 2 is 1280 kbps.
It means, no role of delay from R1-R3 or no bandwidth considered from R1-R3. Please help me as I am trying to find the solution for last 2 months. You would be like GOD for me.
06-16-2009 02:33 AM
Hi, I did it, but load is sharing as 60:13. One thing more, why we have selected 1280Kbs via R1-R3-R2, why we have ignored 1536Kbs ? The only problem is I am not getting exact 5:1.
06-16-2009 02:56 AM
GOOD News...
Finally I found it. I have only one qn now. We have 1536kbs between R1-R3 & 128Kbs between R3-R2. Why we have considered lower one. What about if we reverse the bandwidth I mean R1-R3->128Kbs & R3-R2->1536kbs, then which one I have select in path 2 ?
06-16-2009 05:03 AM
Hello Rupesh,
>> Why we have considered lower one.
This is the way EIGRP metric works:
cumulative in delay
inverse proportional to lowest BW in path. = 10^7/Lowest_BW [kbps]
EIGRP route data structure a TLV (type length value) contains separated fields for all the metric components + the minimum MTU on path.
R1 can easily calculate the path metric from its own point of view by adding link delay to reported distance = received metric fields and by comparing the BW on the link with the BW field value.
see
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800c2d96.shtml
Hope to help
Giuseppe
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