08-19-2025, 10:43 AM
In EIGRP, two routers will only form a neighbor adjacency if their K-values (metric weights) match. The K-values correspond to the metric calculation formula and must be identical across all peers in the same EIGRP AS. By default, Cisco uses the values "0 1 0 1 0 0" but none of the options are using these k-values. Hence, we choose which fits best.
When we configure metric weights, the first value is TOS which is always 0. Which means only two options remain.
K5 must be 0 unless K4 > 0, otherwise the reliability term can be rejected. Many IOS versions reject such combination.
This leaves us with only one correct combination "metric weights 0 1 1 1 0 0". Although these aren't default values but are the only ones correct.
When we configure metric weights, the first value is TOS which is always 0. Which means only two options remain.
K5 must be 0 unless K4 > 0, otherwise the reliability term can be rejected. Many IOS versions reject such combination.
This leaves us with only one correct combination "metric weights 0 1 1 1 0 0". Although these aren't default values but are the only ones correct.