FD Calculation

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Many thanks to all those who respond.

OK here is the scenario; focus on network 222.222.222.0

router#sh ip eigrp top
IP-EIGRP Topology Table for AS(1)/ID(192.168.100.2)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 192.168.100.0/24, 1 successors, FD is 1761792
         via Connected, Serial0/1
P 172.16.31.0/24, 1 successors, FD is 2169856
         via Connected, Serial0/0
P 172.16.0.0/16, 1 successors, FD is 2169856
         via Summary (2169856/0), Null0
P 222.222.222.0/24, 1 successors, FD is 1761792
         via 192.168.100.2 (1761792/28160), Serial0/1




-------------------------------


Router#sh ip eigrp top 222.222.222.0 255.255.255.0
IP-EIGRP topology entry for 222.222.222.0/24
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is
1761792
  Routing Descriptor Blocks:
  192.168.100.2 (Serial0/1), from 192.168.100.2, Send flag is 0x0
      Composite metric is (1761792/28160), Route is Internal
      Vector metric:
        Minimum bandwidth is 2048 Kbit
        Total delay is 20000 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1



The FD is 1761792 the AD is a direct link into that network so this is
just one link!



BW + Delay does NOT = the FD


10,000,000 / 2048 *256 = BW part of the metric


20000 * 256 = delay part of metric

add the two and you should have your metric, do i then add the AD as
well?
 I've tried a few combinations but no luck reaching that figure.


Thanks


Re: FD Calculation
stropiter wrote:
Quoted text here. Click to load it

Almost. remember where the metrics come from. They are eigrp metrics, scaled by
256. I am not 100% certain if the individual parts of the metric are scaled, or
if the final is scaled.

try again, using:

INT(10,000,000 / 2048) *256 = BW part of the metric

Item    Value    igrp    eigrp
Band    2048    4882    1249792
Delay    20000    2000    512000
Total        6882    1761792
--
Paul Matthews                          
paul@cattytown.me.uk
http://www.hepcats.co.uk

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