Starting September 9th and lasting through September 15th, Microsoft will be conducting a daily, 2 hour brownout test for Azure DevOps. This will be the first test. The reason for the brownout is for new IP address ranges to be implemented to allow customers to use Azure Service Tags to manage the traffic flow between Azure Services and on-prem systems. For a complete explanation on what is changing, when it will be implemented, and the details behind the rollout plan, be sure to visit the post at

New IP address ranges with Service Tags for Azure DevOps Services