skitter vs BGP (topology vs routing) BGP routeviews: 37 peers, 9.4K ASes, ~100K prefixes skitter: 17 monitors, 400K dsts, 50K prefixes to equalize, have to reduce skitter to AS graph: 0) pick one trace per prefix per day ignore nodes next to non-responding hops 1) strip IP leaves 2) convert IP -> prefixes 3) strip prefix leaves 4) convert prefix -> AS 5) strip AS leaves