Complex interaction between failures and BGP


BGP after path failure (33% of maskable failures)
BGP reacts to failure (convergence)

BGP before path failure (24%)
Protocol causes outage: route flap damping
Operator causes outage: maintenance, misconfiguration, etc.
Coarse probing: BGP seen before probes notice outage

No BGP associated with path failure (43%)
Aggregation, path diversity within ISP, etc.