Cloudflare’s perspective of the October 30 OVHcloud outage

On October 30, 2024, OVHcloud, a global cloud hosting provider, experienced a significant outage lasting approximately 17 minutes. The incident affected traffic between OVHcloud and Cloudflare, with peered traffic volume dropping significantly during the event. OVHcloud's postmortem report attributed the issue to an erroneous network configuration push by one of their peering partners. Upon investigation, Cloudflare found evidence of a maximum prefix-limit threshold being breached on its peering session with Worldstream in Amsterdam, which led to the BGP session entering an idle state and preventing the route leak from impacting Cloudflare's network. The incident highlights the importance of implementing measures such as max prefix-limits, ASPA for BGP, and RPKI to prevent future route leaks and enhance overall Internet resilience.