On the Deployment of Default Routes in Inter-domain Routing

In this paper, we argue that the design of a responsible Internet requires a clear understanding of the current state of deployment. This work sheds light on default routing in the Internet, a routing strategy that reduces control but may help to increase availability when forwarding packets. We revisit and extend two common methodologies based on active measurements to increase coverage and accuracy. Our results show larger differences in the results between the methodologies. We confirm that default route deployment strongly correlates with the customer cone size of autonomous systems and that smaller networks are more likely to deploy a default route. Our data will help to better assess the deployment of other protocols such as RPKI route origin filtering.