Multi-path inter-domain routing : The impact on BGP ’ s scalability , stability and resilience to link failures

Boarder Gateway Protocol (BGP) is a critical part of the Internet, as it is the protocol that keeps the Autonomous Systems (ASes) connected. Despite the fact that it managed to scale to the current Internet’s size, it also faces other problems, one of them being transient disconnectivity during convergence time. In the last years, efforts to solve this problem concluded with the proposal of multi-path routing protocols. As their name implies, these protocols are designed to explore more paths than BGP in the attempt to keep the ASes connected in case of link failures. In this thesis we try to shed more light over the multi-path routing protocols by conducting experiments that show their behavior and impact on BGP. We focused on three multi-path protocols, i.e. R-BGP, YAMR and STAMP, and devised scenarios and experiments to show their impact on BGP’s scalability, stability and resilience to link failures. Our results show that R-BGP outperforms the other two methods, being the only one that maintains continuous connectivity during convergence time and at the cost of the smallest number of extra BGP messages.