Abstract
In this paper, variational principles from theoretical physics are used to describe the process of routing in computer networks as an alternate approach to the traditional graph theory principles. The total traffic currently served on all hops of the route has been chosen as the quantity to minimize. A universal metric has been found for dynamic routing, taking into account the packet loss effect. An attempt was made to derive the metrics of the most popular dynamic routing protocols such as RIP, OSPF, EIGRP from the universal metric.