Microsoft reports DNS issues as solved (Feb. 11, 2019)

[German]Microsoft believes that the DNS issues that caused failures at various services, including Windows Update, in January/February 2019 have now been finally fixed. Meanwhile all Microsoft services should be usable again.


Service outages in Jan./Feb. 2019

At the end of January, beginning of February 2019, there were numerous failures in Microsoft services, from Microsoft Azure to Office365 to the fact that Defender or Windows no longer received updates. Here is a corresponding tweet:

It didn’t hit every user, some were able to use the services, others were affected from time to time. I had reported that within my blog post Windows Update Service globally disturbed? (01/31/2019). Later, Microsoft cited a malfunction of a DNS provider as one of the causes. Here is Microsoft’s statement:

Root Cause: An external DNS service provider experienced a global outage after rolling out a software update which exposed a data corruption issue in their primary servers and affected their secondary servers, impacting network traffic.

A subset of Azure services, including Azure Active Directory were leveraging the external DNS provider at the time of the incident and subsequently experienced a downstream service impact as a result of the external DNS provider incident.

Azure services that leverage Azure DNS were not impacted, however, customers may have been unable to access these services because of an inability to authenticate through Azure Active Directory.

See also the details outlined within my blog post Azure Active Directory outage & RCA for Azure Cloud hicups.

Microsoft believes the issue is fixed

Microsoft had already reported at the beginning of February 2019 that the DNS issues had been fixed. But apparently it took days until the fixed DNS records on all DNS servers worldwide were updated. Now Microsoft has updated its Windows 10 and Windows Server 2019 update history page. There you will find the following text:


February 11, 2019 12:45 PM PST

Windows Update customers were recently affected by a network infrastructure event caused by an external DNS service provider’s global outage. A software update to the external provider’s DNS servers resulted in the distribution of corrupted DNS records that affected connectivity to the Windows Update service. The DNS records were restored by January 30, 2019 (00:10 UTC), but downstream effects continued. We believe the issue to be fully mitigated because the majority of local Internet Service Providers (ISP) have refreshed their DNS servers and customer services have been restored. If you are still encountering download failures, please contact your local ISP.

While this was not an issue with Microsoft’s services, we take any service disruption for our customers seriously. We will work with partners to better understand this so we can provide higher quality service in the future even across diverse global network providers.

Now Microsoft believes that the DNS issue has been finally fixed, and I haven’t seen complains about that within the last days. (via)

Similar articles:
Windows Defender with Update issues (01/30/2019)?
Windows Update Service globally disturbed? (01/31/2019)
Office365 outage: a status update (01/26/2019) outage fixed, Microsoft 365 facing now new issues 01/29/2019)
Ups, Microsoft deleted Azure Cloud data bases
Office 365 down (January 24, 2019)?
Azure Active Directory outage & RCA for Azure Cloud hicups

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