Last Updated on August 1, 2021 by Admin 1
Which parameter does EIGRP use to compute the bandwidth part of the metric?
- The maximum bandwidth link in the path, in kilobits per second
- The minimum bandwidth link in the path, in kilobits per second
- The average bandwidth of all the links in the path, in kilobits per second
- The average bandwidth of all the links in the path, in kilobytes per second
The minimum bandwidth link, in kilobits per second, is used in the EIGRP metric calculation, because this is the limiting factor in the overall speed of delivery over the path.
BW = (10,000,000 / bandwidth in Kbps) x 256
Delay = (delay in microseconds / 10) x 256
The formula for calculating the EIGRP metric is shown below:
[K1 x BW + (K2 X BW) / (256 – load) + K3 x delay] X [K5 / (reliability + K4)]
You should note, however, that when K5 = 0 (as it is by default), a slightly different formula applies.
When K5 = 0, the EIGRP metric is [K1 X BW + (K2 X BW) / (256 – load) + K3 x delay]
By default, K1 = 1, K3 = 1, and K2, K4, and K5 = 0.
Therefore, the default EIGRP metric is BW + Delay, where “BW” and “Delay” are determined according to the formula above.
The final formula is shown below:
[10,000,000 / (bandwidth in Kbps) + (delay in microseconds) / 10] * 256
These usually are derived from the values listed in the show interfaces command.
Objective:
Layer 3 Technologies
Sub-Objective:
Describe and optimize EIGRP metrics