Microsoft’s cloud-services team has traced the most recent outage for its western European customers to a bad configuration of a network device.

The service interruption of Windows Azure services on 26 July lasted about 2.5 hours, affecting customers using compute services on Microsoft’s cloud hosted in one or more of the company’s western-Europe data centers.

“The service interruption was triggered by a misconfigured network device that disrupted traffic to one cluster in our West Europe sub-region,” Mike Neil, general manager for Windows Azure, wrote in a blog post.

“Once a set device limit for external connections was reached, it triggered previously unknown issues in another network device within that cluster, which further complicated network management and recovery.”

Neil apologized to affected customers and advised them to contact support and file for service-level-agreement (SLA) credit. More information is expected to come out of the ongoing root-cause analysis sometime this week, he said.

The Azure infrastructure has eight nodes in Europe, eight in the US and another eight across Asia-Pacific, Qatar and Brazil.

Microsoft offers a variety of public-cloud services on the Azure platform, including scalable web hosting, Platform-as-a-Service (PaaS) for developers, PaaS specifically for Apache Hadoop and a raw Infrastructure-as-a-Service offering, launched only recently.