Delay is a static metric assigned to each interface using the ‘delay’ interface command. this metric estimates the serialization delay incurred by the interface. Since delay can vary depending on the interface, this should be considered more of an average delay for typical traffic.
Delay is represented in tens of microseconds units. Configuring delay to 123 means 1230 microseconds. the ‘show interface’ command already displays delay direction in microseconds. If no delay is configured ISO assigns an implicit delay value to the interface depending on the hardware type.
When calculating delay into the composite metric, EIGRP takes the total delay into account. This is done by taking the delay as advertised by a neighbor and summing it with the delay of the interface toward the neighbor.
Classic Metrics EIGRP describes delay in the range of 10 to 167,772,140 microseconds. 16,777,215 is known as an infinite distance and is the key to advertising an unreachable network.