Incident MO888473 – Was M365 down?

Users and customers in the US started reporting issues with logging into and using M365 early Thursday the 12th. Downdetector got thousands of reports and it didn’t take long for Microsoft to send out a M365 Health Status update.

Our analysis of data for US environments showed the following: first of all, looking at the real-time scores (compaired to expected normal), the various M365 services were definitely showing an impact, but not catastrophically. Scores below 85 indicate an impact to service but not necessarily an environment wide outage. So these numbers could hint at various things. Perhaps not all regions and users were hit, perhaps it was related to specific networks or ISP’s or perhaps the problem was already resolving itself. Microsoft had not reported this yet at the time our system made us aware of the issue.

Scores were specifically indicating issues with authentication (<85). API & Network scores were significantly above 90 (normal), so the next step was looking at the data for authentication.

And indeed, the timelines showed a clear impact on authentication for multiple services. It also shows that at the moment of checking they were already on the way to being resolved which would explain why the numbers were already getting back to normal. However, this still does not tell us who was affected. Drilling down though showed quickly that it was specifically the users of the ISP AT&T who were severely impacted and still feeling the after effects:

… especially in comparison to users of other ISPs in North America.

The confirmation followed not much later with Microsoft confirming an ISP specific cause for the issue through their X channel as well as Admin Center:

At the point of writing this, AT&T hasn’t formally confirmed that it was the source of the outage, but other sites like Forbes and ZDNet mention it as the most likely ISP.

OfficeExpert TrueDEM not only quickly identified the issue in real-time, it accuratly indicated where the problem was (ISP), what was impacted and who was impacted. This allowed administrators to correctly gauge the scope and impact. The were able to provide workarounds and address impacted users specifically, well before Microsoft provided the information.

Do you want to know more about how OfficeExpert TrueDEM accomplishes this? Contact us to see how OfficeExpert TrueDEM can help your organization quickly identfiy and resolve issues with M365 or Teams calls.