So when we enable or disable a K value, actually we enable or disable its associate metric component. EIGRP uses four components out of five to calculate the routing metric….K-Values and EIGRP Metrics.
| K Value | Component | Description |
|---|---|---|
| K1 | Bandwidth | Lowest bandwidth of route |
| K2 | Load | Worst load on route based on packet rate |
Does EIGRP support unequal-cost load balancing?
One magic word enables unequal-cost load balancing in EIGRP. The variance command is a multiplier and has a default value of 1. The router will multiple the Feasible Distance of the route by the variance value. Any feasible successor with a metric less than that new value will be entered into the routing table.
How do you configure equal cost load balancing in EIGRP?
By default, EIGRP supports equal-cost load balancing over four links. Equal-cost means that multiple routes must have the same metric to reach the destination, so that router can choose to load balance across equal cost links. To better understand the equal-cost load balancing concept, consider the following example.
How do you calculate EIGRP metric and K values?
The formula we use for the metric calculation looks like this:
- Metric = [K1*bandwidth + ((K2*bandwidth)/(256-load))+K3*delay]
- Metric = Metric*[K5/(reliability+K4)]
- Metric = bandwidth (slowest link) + delay (sum of delays)
- Metric = (107 / minimum bandwidth) * 256 + (sum of delays) * 256.
How does EIGRP calculate cost?
It is calculated by adding the advertised/reported distance advertised by the neighbor and the cost calculated by that current router to reach the neighbor. successor: It is the (lowest) best path to reach to any specific destination network.
Does EIGRP load balance by default?
EIGRP load balancing By default, EIGRP supports equal-cost load balancing over four links. Equal-cost means that multiple routes must have the same metric to reach the destination, so that router can choose to load balance across equal cost links.
What is equal cost load balancing?
Equal-cost load balancing, as its name implies, is the balancing of a traffic load across redundant links of equal cost. This alleviates the potential for problems caused by per-packet load balancing but can result in a somewhat less than perfect distribution of traffic across equal-cost links.
What is equal and unequal cost load balancing?
EIGRP Equal-Cost and Unequal-Cost load balancing Routes with lowest metric get installed in the routing table by default, if two or more routes having the same metric the router will install both the routes in the routing table this is called equal cost load balancing.
How does EIGRP determine load balancing?
Configure Load Balancing on Cisco EIGRP using Unequal Routes
- Examine the current best route to the destination. On the originating router, use command show ip route [destination IP] to show the best route to reach the destination IP.
- Identify EIGRP Feasible Successor (FS) routes.
- Configure the variance value.
Does EIGRP use cost?
Despite how flexible the cost calculation is, most implementations of EIGRP just rely on the default K-values for their metric. The default K-values consider only Bandwidth and Delay, and ignore Load and Reliability.
