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New Member

EIGRP FD value calculation--URGENT

dear all,

pls find the attachment of my query, and provide your suggestions ASAP

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

Re: EIGRP FD value calculation--URGENT

Hello Sourabh,

the issue here is your desire to understand the EIGRP metric.

Here are some notes about EIGRP way to calculate metrics

256 * (sum of delays in 10s of microseconds)

256 * (500 +2000+2000) = 1152000

256 * (4500)= 1152000

bw component is the inverse of the smallest BW in the path in kbps

256 * 10^7 / 1544 = 1658031

total = 2810031

not so different from 2809856 that appears in your routers.

Again FD is the best metric from the point of view of the local node (R4)

EIGRP metric is cumulative in delay but inverse proportional to the lowest BW in path so the fact that R1's loop0 has BW 8000000..... kbps has no effect in EIGRP metric calculation.

other point is that you need to divide by 10 the value you read of delay in the various sh interface because EIGRP uses tens of microseconds

Hope to help

Giuseppe

3 REPLIES
Hall of Fame Super Gold

Re: EIGRP FD value calculation--URGENT

Please use only .txt format attachments and do not solicit for urgency - this is a free forum, if you need guaranteed support use the TAC.

Hall of Fame Super Silver

Re: EIGRP FD value calculation--URGENT

Hello Sourabh,

the issue here is your desire to understand the EIGRP metric.

Here are some notes about EIGRP way to calculate metrics

256 * (sum of delays in 10s of microseconds)

256 * (500 +2000+2000) = 1152000

256 * (4500)= 1152000

bw component is the inverse of the smallest BW in the path in kbps

256 * 10^7 / 1544 = 1658031

total = 2810031

not so different from 2809856 that appears in your routers.

Again FD is the best metric from the point of view of the local node (R4)

EIGRP metric is cumulative in delay but inverse proportional to the lowest BW in path so the fact that R1's loop0 has BW 8000000..... kbps has no effect in EIGRP metric calculation.

other point is that you need to divide by 10 the value you read of delay in the various sh interface because EIGRP uses tens of microseconds

Hope to help

Giuseppe

New Member

Re: EIGRP FD value calculation--URGENT

thank you my friend

i got the correct value

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