BGP Route Reflectors (RR), which are commonly used to help scale Internal BGP (iBGP), can produce oscillations, forwarding loops, and path inefficiencies. ISPs avoid these pitfalls through careful topology design, RR placement, and link-metric assignment. This paper presents Address-Based Route Reflection (ABRR): the first iBGP solution that completely solves all oscillation and looping problems, has no path inefficiencies, and puts no constraints on RR placement. ABRR does this by emulating the semantics of full-mesh iBGP, and thereby adopting the correctness and path efficiency properties of full-mesh iBGP. Both traditional Topology-Based Route Reflection (TBRR) and ABRR take a divide-and-conquer approach. While TBRR scales by making each RR responsible for all prefixes from some fraction of routers, ABRR scales by making each RR responsible for some fraction of prefixes from all routers. We have implemented a fully functional ABRR prototype. Using BGP data from a Tier-1 ISP, our analytical and implementation results show that ABRR's scaling and convergence properties compare positively with traditional TBRR.
['Ruichuan Chen', 'Aman Shaikh', 'Jia Wang', 'Paul Francis']
Address-based route reflection