Traceroute & Routing Analysis
Traceroute is how you turn “the internet is slow” into a concrete path-level story: where the traffic goes, where latency begins, and whether the route is changing over time. This pillar is focused on interpreting hop behavior without jumping to the wrong conclusion.
Related tools
- Traceroute Map — visualize hop paths.
- ISP Info — identify providers/ASNs involved.
- Subnet Calculator — validate addressing and planning.
- Outage Detector — confirm upstream incidents.
How to read traceroute without getting fooled
- One slow hop doesn’t always matter: routers may rate-limit ICMP replies while still forwarding traffic normally.
- Look for “downstream confirmation”: if hop 6 is slow but hops 7–N are normal, hop 6 is probably just de-prioritizing replies.
- Route changes are signal: different paths at different times can indicate load balancing, policy changes, or instability.
- Asymmetry is real: forward and return paths may differ; traceroute shows only one direction’s hop responses.
Common scenarios
Latency begins at a specific hop and stays high
Strong indicator of congestion or a constrained link. Capture the hop where inflation starts, then validate provider/ASN with ISP Info and document timestamps.
Traceroute stops mid-path
Many networks block or rate-limit traceroute probes. If the destination is still reachable (ping/HTTP works), treat “stars” as incomplete visibility—not guaranteed failure.
Recommended workflow
- Run Traceroute Map to capture the path.
- Use ISP Info to identify the upstream providers involved.
- If it looks like an upstream event, confirm with Outage Detector.