How this Tool Works: Return Path Analysis
Unlike a standard traceroute or ping which measures reachability, this tool analyzes routing policy. We send traffic to the target network, but we measure how the target chooses to send traffic back to us.
- The Question: Does the remote network prefer Research & Education (R&E) paths over Commodity paths?
- The Mechanism: We watch which interface the return traffic arrives on to infer their BGP Local Preference.
Enter a specific IPv4 Address (to probe a single host) or a CIDR Prefix.
Probing targets, please wait...
Return Path Analysis — [Target]
Analysis Complete
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Longest Prefix Match: --
Probed addresses from the ISI History dataset — showing how each responded:
BGP Visibility
We looked for the prefix in RouteViews. Does an R&E backbone (Internet2) see a route to this prefix?
| Provider | Visibility Status | AS Path Length |
|---|
Why this matters: Shorter paths via Internet2 are preferred. If missing, traffic defaults to commodity.
