# EIGRP Feasible Distance

Video Activity

EIGRP Feasible Distance FORMULAS!!! Oh No!!! Well, no worries, it's looks complex, but it's not and we'll show you why. For this lesson we cover the topic Feasible Distance and demonstrate how EIGRP uses it as its metric using this EIGRP Formula. We decipher the EIRGP Formula and explain in detail what each element of the formula is and what the ca...

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Time
29 hours 18 minutes
Difficulty
Intermediate
Video Description

EIGRP Feasible Distance FORMULAS!!! Oh No!!! Well, no worries, it's looks complex, but it's not and we'll show you why. For this lesson we cover the topic Feasible Distance and demonstrate how EIGRP uses it as its metric using this EIGRP Formula. We decipher the EIRGP Formula and explain in detail what each element of the formula is and what the calculation groupings tells us. For example, there are several factors that comprise the formula such as bandwidth, load level, reliability factor, EIGRP delay and other factors. This lesson is exceptionally good at explaining each component, how they are related and interrelated, what the parameters of that component is, why it's important and how it plays into the entire EIGRP process from a mathematical and execution perspective. Quick and Painless!

Video Transcription
00:04
Okay, guys, don't be scared. I go away and I come back. And there's a scary looking formula on the on the board. It's not hard, and I will simplify this for you.
00:14
So, yes, J. R. P uses feasible distance
00:19
as this metric and what is feasible distance to find out. Well feasible distance is defined as
00:26
well defined in this formula. So K one into bandwidth
00:30
and I would swim. What K is
00:32
plaice skate you into band with over 2 56 minus the load on the link
00:37
or the current traffic on the link
00:40
plus K three into delay The delay of the link? The delay a packet will incur while transporting that link
00:48
multiplied by care five
00:50
divided by care for into reliability, that reliability of the link being how many times in the past hour sold this ring cast failed and come back up
01:00
mount of the whole thing multiplied or scaled up two by 2 56
01:07
Now
01:07
the band with for AARP is actually tend to the power seven,
01:12
divided by the Louis bandwidth between your current position and the destination between the source and the destination.
01:22
The AARP delay is defined as the sum of all delays between source and destination in units off tens off microseconds, though, this little U stands for microbe.
01:34
So whatever the total delays, we will simply divided by 10 because it has to be in units of tens of microseconds
01:42
by default. These K values
01:46
K one and K three are one and kid 24 and five are set to defy zero by default.
01:53
If Kay 50 then you ignore this half of the formula, which is weird. It doesn't work like that in mathematics, but it's discourse for a call. Cisco's rules.
02:04
So if K 50 you ignored this half of the formula,
02:07
kid values range between zero and 255
02:12
Now what exactly is a K value?
02:14
Here is nothing but a weight. It's a *** that you can turn so by default. Okay, one and K three are one, and everything else is set to zero.
02:23
When if I wanted Ta Joppy to also consider the load of the link
02:28
while making its calculations to find which the best route is with the Louis feasible distance, then I might want to increase
02:36
the K to value from zero to maybe five. I wanted to consider the load on the link a little bit more than bandwidth, or I wanted it to consider the loan on the link. Ah, lot more than band with. I can set this to
02:49
255 K to allude to 255
02:52
What if I want a job for you to consider only the delay of the link and not the band with? Well, I can set k 1 to 0 all of the K values to zero, and I can set K three, which is multiplied by delay to a high number or just one.
03:07
If I want your Joppy to only consider bandwith while making his calculation, I can set all other K values to zero, and I can just set k one to the number one or a higher value.
03:20
Now, as I said, T one and K three are won by default and every other K value is zero. Let's see what happens to our formula
03:30
once we set the K values
03:32
20
03:35
it's okay to four and five are zero.
03:38
So if
03:38
care to a 00 into something a zero so this goes to zero
03:46
Okay, this whole portion goes to zero. If k 50 we ignore this side of the formula. So the formula produces down to K. One is one.
03:55
Anyone? Anything multiplied by one is the same number.
04:00
So ban with plus
04:03
que trees one anything multiplied by one again is one
04:09
delay whole thing multiplied by
04:12
2 56 The fish feasible distance formula reduces down to bandwidth plus delay if default values are being used
04:23
multiplied by 2 56 scaled up by 2 56
04:26
This concludes the metric portion or the feasibility feasible distance portion of the lecture.
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