Instability free routing: beyond one protocol instance

Today, a large body of research exists regarding the correctness of routing protocols. However, many reported global disruptions of Internet connectivity, e.g., inter-AS persistent loops, cannot be explained by looking at a single routing protocol at a time. In fact, these anomalies have long been suspected in the operator community to be caused by the interactions between routing protocols. The interactions between protocol instances are governed by two procedures at the border routers: route selection (RS) ranks routes from different protocol instances; and route redistribution (RR) exchanges routes between protocol instances. Prior studies hypothesized that RR may be responsible for a portion of the observed anomalies. In this paper, we provide analytical and experimental results to link RS, RR, and their interplay to anomalies discovered in operational networks. We show that RS by itself can cause route oscillations and loops, and that in all Cisco, Quagga, and XORP implementation...

• Type: Conference
• Year: 2008
• Where: CONEXT
• Authors: Franck Le, Geoffrey G. Xie, Hui Zhang
• Keywords: Computer Networks, CONEXT 2008, Protocol Instances, Routing Protocols, Single Routing Protocol