Why does EIGRP use the lowest bandwidth?

[DaniloB]

Hey all. I'm trying to understand how EIGRP works regarding the best path selection and I can't figure out why it uses the lowest bandwidth in the path from A to B: according to the formula, the highest the bandwidth, the highest the metric. I'd expect traffic to be sent over the highest bandwidth link but it doesn't seem to be the case with EIGRP. Can someone shed some light on this?

[Carlos Villagran]

Hi!

Other element in the formula is Delay, so I recommend you to check this value and also complete metric numbers in the show ip eigrp topology command. 

Hope it helps, best regards!

JC

[DaniloB]

Um.. according to the formula, the highest the Delay, the highest the metric.. which makes even less sense to me : / I don't understand, why does EIGRP use the worst link in the path?

[SJ K · Accepted solution]

Hi Danilo,

Just my 2 cents,  from point A to point B, you might go through several hops.

The path with the lowest bandwidth is the choking point of the entire path.

EIGRP use the lowest bandwidth in the path for calculating the FD of the path, it does not necessarily means that it will use the path with the lowest bandwidth.

Regards,
Noob

[DaniloB]

Got it! It takes into account the bottleneck to calculate the metric, it makes perfectly sense now. Thanks!