EIGRP load balancing based on interface load

EIGRP computes its composite metric from five parameters, one of them being interface load, therefore raising the theoretical possibility of having route metrics that include interface load. However, tweaking EIGRP K-values with the metric weights command to include interface load in metric calculations is highly discouraged - every change in interface load could lead to network instability. Even worse, whenever an interface load would increase, the increased composite metric of the afftected routes in EIGRP topology table would cause them to enter active state (and the router to start the DUAL algorithm trying to find more optimum paths toward the destination).

To make the whole idea even more impractical, EIGRP does not scan the interface load (and other parameters influencing the metric) on periodical basis, but only when triggered by a change in network topology (for example, interface or neighbor up/down even).

Note: this article is part of You've asked for it series.

2 comments:

You don't have to log in to post a comment, but please do provide your real name/URL. Anonymous comments might get deleted.

Ivan Pepelnjak, CCIE#1354, is the chief technology advisor for NIL Data Communications. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.