- Within EIGRP topologies, the EIGRP Wide Metrics feature allows for the calculation of 64-bit metrics as well as the scaling of the Routing Information Base (RIB).
- Only in EIGRP named mode settings are the 64-bit calculations able to function properly. EIGRP classic mode configurations make use of calculations that are 32 bits in size.
- In order to allow for the adjustment of EIGRP metric computations and to identify the type of service (ToS), EIGRP monitors metric weights on an interface by utilizing K values. The K values are integers that range from 0 to 128; these integers, along with other variables such as bandwidth and delay, are utilized in the process of calculating the overall EIGRP composite cost measure.
- The default configuration uses the latency and bandwidth metrics to generate a single 32-bit metric, with bandwidth taking precedence. However, you can modify K values to provide other routing behaviors. 256*(Scaled Bw + Scaled Delay) is the default formula that is reduced from the previously described composite cost metric when the default constants are used.
