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Technical Reports: CMU-CyLab-07-002

Title:Would Diversity Really Increase the Robustness of the Routing Infrastructure against Software Defects?
Authors:Juan Caballero, Theocharis Kampouris, Dawn Song, Jia Wang
Publication Date:February 6, 2007


Today’s routing infrastructure exhibits high homogeneity. This constitutes a serious threat to the resilience of the network, since a bug or security vulnerability in an implementation could make all routers running that implementation to become simultaneously unusable. This situation
could arise as a defective software upgrade or a denial-ofservice attack.

Diversity has been proposed as a solution to increase the resilience to software defects, but the benefits have not been clearly studied. In this paper, we use a graph theoretic approach to study those benefits, addressing three fundamental questions: 1) how to measure the robustness of the network to such failures; 2) how much diversity would be needed for a certain degree of robustness; and 3) how to best use the available diversity.

We find that a small degree of diversity can significantly increase the robustness of the network against software defects. We observe that for small networks, partitioning the network into contiguous regions that use the same implementation, works best. For large ISP networks, where routers usually have roles, the best approach is to apply diversity to each role separately. We evaluate our approach on multiple real ISP topologies, including the topology of a Tier-1 ISP.

Full Report: CMU-CyLab-07-002