Exam 200-301 | Question id=5374 | IP Connectivity |
Which of the following is NOT a possible component of Enhanced Interior Gateway Routing Protocol's (EIGRP) composite metric?
A. |
Cost | |
B. |
Load | |
C. |
Delay | |
D. |
Bandwidth |
Cost is not a component of EIGRP's composite metric. The cost, or efficiency, of a path is used as a metric by the Open Shortest Path First (OSPF) routing protocol.
Enhanced IGRP (EIGRP) is Cisco Systems' proprietary routing protocol. It can use bandwidth, delay, load, reliability, and maximum transmission unit (MTU) to calculate the metric. Of these five metrics, by default, only minimum bandwidth and delay are used to compute the best path.
The metric for EIGRP can be calculated with this formula:
Metric = [K1 * Bandwidth + (K2 * Bandwidth) / (256-load) + K3*Delay] * [K5 / (reliability + K4)]
The default constant values for Cisco routers are K1 = 1, K3 = 1, and K2 = 0, K4 = 0, K5 = 0. In the default setting, K1 and K3 have non-zero values, and therefore, by default, the metric is dependent on bandwidth and delay.