Debugging Routing & Forwarding Using RIPE Atlas#

Randy Bush, Internet Initiative Japan

• Why: Two real cases where external vantage points found in minutes what provider NOCs couldn't find in weeks — cheap, adoptable debugging technique.
• What: Case 1: a serial-console server on a colo LAN became unreachable; the provider's week of debugging failed, one Atlas global/random traceroute found the problem (with hover-text and clickable hop detail as the "smoking gun"), fixed within an hour. Case 2: a friend's IPv6 was unrouted for months while the ISP NOC saw nothing; 15 Atlas probes inside that same ISP exposed the internal routing problem to a senior engineer within hours.
• How: RIPE Atlas (12,000+ probes) one-off measurements and traceroute visualizations, plus the measurement API for automation. Bush closes with a challenge: build an AI front-end that takes a problem description and drives the Atlas API to diagnose it — a nice framing of where troubleshooting tooling is heading.
• Where applicable: Anyone; free to use if you host a probe (membership not required). Scale- and vendor-agnostic.