Analysis of the MED Oscillation Problem in BGP

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Analysis of the MED Oscillation Problem in BGP
The Multi Exit Discriminator (MED) attribute of the Border Gateway Protocol (BGP) is widely used to implement “cold potato routing” between autonomous systems. However, the use of MED in practice has led to BGP persistent oscillation. The MED oscillation problem has been described with example configurations and complicated, step-by-step evaluation of dynamic route computations performed at multiple routers. Our work presents the first rigorous analysis of the MED oscillation problem. We employ the Stable Paths Problem (SPP) formalism that allows a static analysis of the interaction of routing policies. We give a formal definition of MED Induced Routing Anomalies (MIRA) and show that, in general, they can span multiple autonomous systems. However, if we assume that the BGP configurations between ASes follows a common model based on customer/provider and peer/peer relationships, then we show that the scope of any MIRA is always contained within a single autonomous system. Contr...
Timothy Griffin, Gordon T. Wilfong
Added 14 Jul 2010
Updated 14 Jul 2010
Type Conference
Year 2002
Where ICNP
Authors Timothy Griffin, Gordon T. Wilfong
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