Eliminating Routing Loops and Oscillations in BGP Using Total Ordering

Abstract

OPERA is a framework recently introduced that formalizes routing etiquettes based on path information. New rules derived from OPERA to provide total ordering among paths are added to the policy mechanisms used in IBGP and EBGP, which results in OPERA-based BGP (OBGP). OBGP is a complete loop-free inter-domain multi-path routing solution based on IBGP and EBGP. OBGP is proven to be stable and loop-free at every instant. Well-known examples of systems in which IBGP and EBGP do not converge are used to illustrate the benefits of OBGP.