BGP Rerouting Solutions for Transient Routing Failures and Loops

During the routing convergence processes of BGP system, the end-to-end reachability can be temporarily disrupted due to transient routing failures or loops in the forwarding paths. This could lead to severe performance degradation and even service disruption, especially for the real-time interactive applications. In this paper, we explore feasible modifications of BGP to eliminate transient routing failures and loops. First, we find that the existing BGP convergence acceleration solutions, such as ghost-flushing and EPIC, can eliminate transient forwarding loops but exacerbate transient routing failures. Then we propose an indicative re-routing scheme, which enable BGP to piggyback an indicator of alternative paths with each route, to improve route visibility and thus eliminate transient routing failures. However, we find that it might worsen transient forwarding loops at the same time. Finally, we exploit the synergy of the combination of the two types of schemes and propose an indicative+EPIC rerouting scheme. It is found capable of eliminating both transient forwarding failures and loops