Microsoft Details 5-Hour West US Azure Outage After Automated Route Error
Updated
Updated · Computerworld · Jul 24
Microsoft Details 5-Hour West US Azure Outage After Automated Route Error
3 articles · Updated · Computerworld · Jul 24
Summary
Microsoft said West US Azure and cloud services lost external connectivity for nearly five hours on July 23, from 14:44 UTC to 19:41 UTC, while workloads running entirely inside the region stayed up.
An automated isolation process during routine fiber maintenance removed IP routes in error, expanding beyond the devices in the original plan and cutting traffic entering and leaving the facilities.
Customers flagged the disruption quickly, and Microsoft engineers identified the fault within the first hour before restoring connections.
Microsoft said the incident was tied to recent fiber maintenance activity and urged organizations with mission-critical data to use a multi-region setup to reduce similar risks.
The outage was Microsoft's second major cloud disruption this year, following a 10-hour February incident that hit both the US West and US East regions.