Customers may have been unable to connect to their lab virtual machines (VMs) between Oct 13, 2020 and Oct 15, 2020.
Cause of the outage: Azure Lab Services manages the customers' VMs within internal Azure subscriptions that the service owns (more details on the service's architecture fundamentals here). For internal subscriptions, Microsoft runs regular organizational security rules. Due to recent configuration changes, an internal security rule got applied to the customer VMs inside our subscriptions that blocked VM connections that came from external to Microsoft.
Resolution: The internal security rules that were blocking customers' access to the VMs have been removed, and we have ensured that the internal configurations will no longer be applied to our service's subscriptions that host customer VMs.
This outage has been resolved and customers can now connect to their VMs. If you were affected by the issue, please try starting and connecting to the VMs again.
We apologize for the inconvenience. If you have any questions, please leave us a comment below.