Azure Front Door outage, 30 July 2024

Azure Front Door congestion after DDoS mitigation (30 July 2024). The disruption lasted about 7 hours 58 minutes, according to Microsoft Azure’s own timeline.

What happened. After a routine DDoS mitigation, network routes at one European site could not be updated because of control-plane failures from a local power outage. A latent network misconfiguration also sent traffic from outside Europe to the European DDoS protection system, causing congestion, latency and connection failures.

What changes. Microsoft added missing configuration so a DDoS mitigation issue in one geography can’t spread to another, and is improving validation to detect invalid network configurations.

Questions

What caused the Microsoft Azure outage in July 2024?

After a routine DDoS mitigation, network routes at one European site could not be updated because of control-plane failures from a local power outage.

Which services were affected?

Azure Front Door, Azure CDN, Azure portal, subset of Microsoft 365 and Microsoft Purview.

Read how shared dependencies spread a failure in why one cloud outage can break unrelated apps, or browse the outage archive.