Cases2 cases

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1. IL-0348 Scaleway's FR-PAR region lost public internet connectivity when one 100 Gbps backbone link was saturated

   Scaleway2025

   Symptoms

   On 10 March 2025 at 16:22 UTC, public internet connectivity in Scaleway's FR-PAR region broke for all products. Most internet traffic between the FR-PAR-2 availability zone and the rest of the PAR region was blackholed for about five minutes, while VPC traffic and Dedibox RPN kept working.

   Packet lossService outageHigh latency

   Trigger

   While Scaleway's network team connected a new data center to the FR-PAR backbone, a human mistake in a router configuration rerouted more than 1 Tbps of traffic between OpCore DC3 and DC5 through a single 100 Gbps link.

   Root cause

   Operator error

   Component

   Backbone network (WAN)Object storageAuthoritative DNS servers and records

   Contributing factor

   Automation amplification

   Detection

   The router configuration error was detected quickly and rolled back within four minutes.

   Remediation

   • Rolled back the router configuration, restoring the correct configuration at 16:27 UTC

   Action items

   • Harden the peer review and production communication process for changes
   • Add failsafes and tests before network configuration is applied at backbone level
   • Deploy the fix for the Object Storage synchronisation software issue

   View case
2. IL-0347 About 25% of Scaleway FR-PAR-1 hypervisors lost VPC connectivity when both VPC BGP route reflectors got stuck

   Scaleway2024

   Symptoms

   On 18 October 2024, from 7:50 to 8:01 UTC, about 25% of the hypervisors in Scaleway's FR-PAR-1 availability zone lost VPC connectivity with the rest of the region, and products that use VPC failed with them. Public internet connectivity and Elastic Metal VPC connectivity were not affected.

   Network unreachablePacket lossNode NotReady

   Trigger

   At 6:20 UTC a Top of Rack switch in FR-PAR-1 had a software crash. One of the two BGP route reflectors for VPC ran on a hypervisor in that rack and was left in an abnormal state.

   Root cause

   Software defect

   Component

   Network control plane (SDN)BGP routingNetwork switchDatabaseManaged Kubernetes control plane and provider API

   Contributing factor

   Excessive blast radiusAutomation amplification

   Detection

   Health-check monitoring on both route reflectors detected the anomaly, and the Scaleway Customer Excellence and SRE teams detected the customer impact and opened an incident.

   Remediation

   • Fixed both VPC route reflectors by manual action

   Action items

   • Fixed the autohealing mechanism that had failed to fix route reflectors stuck in a stale state; the fix is https://github.com/FRRouting/frr/pull/17163
   • Run different software versions on the route reflectors so a single bug cannot stop several instances
   • Investigate the software issue that left the route reflectors in a stale state

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