BGP allows routers to use general preference policies for route selection. This paper studies the impact of these policies on convergence time. We first describe a real-time model of BGP. We then state and prove a general theorem providing an upper bound on convergence time. Finally, we show how to the use the theorem to prove convergence and estimate convergence time in three case studies.

We show how to use an interactive theorem prover, HOL, together with a model checker, SPIN, to prove key properties of distance vector routing protocols. We do three case studies: correctness of the RIP standard, a sharp real-time bound on RIP stability, and preservation of loop-freedom in AODV, a distance vector protocol for wireless networks. We develop verification techniques suited to routing protocols generally. These case studies show significant benefits from automated support in reduced verification workload and assistance in finding new insights and gaps for standard specifications.

Network protocols are often analyzed using simulations. We demonstrate how to extend such simulations to check propositions expressing safety properties of network event traces in an extended form of linear temporal logic. Our technique uses the INS simulator together with a component of the MaC system to provide a uniform framework. We demonstrate its effectiveness by analyzing simulations of the ad hoc on-demand distance vector (AODV) routing protocol for packet radio networks. Our analysis finds violations of significant properties and we discuss the faults that cause them. Novel aspects of our approach include modest integration costs with other simulation objectives such as performance evaluation, greatly increased flexibility in specifying properties to be checked and techniques for analyzing complex traces of alarms raised by the monitoring software.

Why are there so few successful "real-world" programming and testing tools based on academic research? This talk focuses on program analysis tools, and proposes a surprisingly simple explanation with interesting ramifications.