On the Stability of Interdomain Routing

Most routing protocols guarantee convergence to a stable routing state. That is, in the absence of topology or configuration changes, each router will eventually find a stable route to any destination. However, this is not the case for policy-based routing protocols, for example, the BGP protocol used as a de facto standard for interdomain routing. The interaction of not-so-complex BGP configurations can cause permanent oscillations of routing. Several models and algorithms have been proposed in the literature to study routing oscillations. This article surveys state-of-the-art contributions in this field, with a special emphasis on algorithmic and combinatorial aspects.