On April 26, 2025, during a planned maintenance window that started at 20:00 UTC, we experienced connectivity problems in eu1: Anaplan Data Center — Netherlands. These problems affected the time needed to restore that region during the maintenance window. As a result, an incident was declared at 01:00 UTC after the maintenance window had ended.
As part of a network change completed during the maintenance window, new routes were added to us1: Anaplan Data Center - U.S. East. During our investigation, we found that these routes had been advertised to dependent regions. This resulted in a logical limit on eu1: Anaplan Data Center — Netherlands being reached. The network was unable to handle new requests, and connectivity was suspended. Once the limit was increased and applied to all switches, full service was restored at 02:33 UTC.
To help prevent similar issues in the future, we’re implementing improved route filtering. This'll stop new routes from being inadvertently advertised across dependent regions. We'll also be adding monitoring for route limits in each region to give early warning if the available routes fall below the agreed limit. Additionally, we're reviewing the interdependencies of routing advertisement between regions and implementing a standardized approach for prefix advertising.
We apologize for any disruption this may have caused to your business. We're committed to improving the reliability of our services and ensuring smoother maintenance in the future.
If you have further questions or concerns, please visit our Support website. Thank you for your patience during this situation and thank you for being an Anaplan customer.