Troubleshooting Variance Problem

Variance is a unique feature of IGRP (and EIGRP) that distinguishes it from RIP. Variance is basically a way to load-balance the traffic on unequal -cost paths.

All routing protocols support equal-cost-path load balancing, but only IGRP and EIGRP support unequal-cost- path load balancing, which is configured using a variance command. Configuration of variance is easy, as long as you know the concept behind it.

The variance command instructs the router to include routes with a metric smaller than n times the minimum metric route for that destination, where n is the number specified by the variance command.