Describes the Enhanced Interior Gateway Routing Protocol and its metric calculation method.
EIGRP is a routing protocol that
-
uses a specific formula to derive total feasible distance from a node to a destination subnet, and
-
does not use the IGP Metric value for each interface.
EIGRP metric calculation
EIGRP uses this formula to derive total feasible distance from a node to a destination subnet:
path metric to destination = (10,000/(bandwidth) + (delay) * 256The formula components are:
-
The bandwidth is the minimum interface Capacity value along the path. This is in Mbps. For each interface, if there is no Capacity value, the Capacity Sim value is used instead.
-
The delay is the sum of the interface delays in 10s of microseconds. This is calculated by taking the sum of the EIGRP Delay values and dividing this sum by 10.
You can set this delay in the EIGRP delay field of an interface's Edit window. Here, the value is in microseconds.
If EIGRP delay is not set, Cisco Crosswork Planning uses 10 as the delay in the preceding calculation, which means 10 "10s of microseconds.". For example, if there are eight interfaces, each with an EIGRP Delay value of 15, the delay used in the calculation is (8 x 15) / 10 = 120 / 10 = 12.
Demands show the EIGRP path metric of the path over which they flow in the Path metric column.