Recent insights on BGP anomalies, zombies, and AS-SET monitoring

Read Articleadded Jan 8, 2026

Cloudflare highlights recent lessons from a Venezuela BGP anomaly, explaining how route leaks arise and how to investigate them. It also details how BGP “zombie” routes persist after missed withdrawals and why they are operationally harmful. Finally, it urges operators to monitor AS-SET memberships and points to Cloudflare Radar as a practical tool for better routing visibility.

Key Points

  • BGP anomalies like the Venezuela event can stem from route leaks and are best understood through careful data analysis and validation practices (e.g., RPKI).
  • BGP “zombie” routes are stale advertisements that remain in the DFZ due to missed withdrawals, and specific operational scenarios make them more likely.
  • Stuck or leaked routes can degrade reachability and stability, underscoring the need for robust filtering, monitoring, and withdrawal handling.
  • Operators should actively monitor and maintain accurate AS-SET memberships, and Cloudflare Radar now assists with this visibility.

Sentiment

The Hacker News discussion exhibits a sentiment of concern, speculation, and diagnostic analysis regarding the specific internet outage in Iran. While not directly agreeing or disagreeing with the article's general routing hygiene recommendations, the discussion implicitly underscores the real-world implications of routing events and the value of monitoring tools like Cloudflare Radar. The dominant sentiment leans towards attributing the outage to a deliberate government action rather than a technical failure.

In Agreement

  • The discussion implicitly highlights the critical importance of real-time network monitoring and data analysis (as provided by Cloudflare Radar) to identify, diagnose, and understand internet routing anomalies, which aligns with the article's emphasis on improved monitoring and validation for better routing hygiene.
  • The concern shown by commenters regarding the widespread impact of the internet outage in Iran implicitly underscores the necessity of robust and secure routing practices, thereby supporting the article's underlying call for improved routing hygiene to prevent or mitigate such disruptive events.