Studying black holes in the internet with Hubble

摘要: We present Hubble, a system that operates continuously to find Internet reachability problems in which routes exist destination but packets are unable reach the destination. Hubble monitors at 15 minute granularity data-path prefixes cover 89% of Internet's edge address space. Key enabling techniques include hybrid passive/active monitoring approach and synthesis multiple information sources historical data. With these techniques, we estimate discovers 85% would be found with pervasive probing approach, while issuing only 5.5% as many probes. also results three week study conducted Hubble. extent problems, both number duration, is much greater than expected, persisting for hours even days, do not correlate BGP updates. In cases, multi-homed AS reachable through one provider, probes another terminate; using spoofed packets, isolated direction failure 84% cases analyzed all exclusively on forward path from provider A snapshot currently can http://hubble.cs.washington.edu.