Microsoft is preparing a significant update that affects how virtual machines in Azure reach the internet. This shift affects new virtual networks beginning March 31, 2026, and it changes the way outbound traffic works by removing default outbound access for newly created VNets. This update is important for anyone responsible for Azure, Cloud Networking, Network Security, or automated deployment pipelines.
What Is Default Outbound Access
Before this change, Azure provided automatic internet access to any virtual machine created inside a new virtual network. If no other networking configuration applied, Azure would fall back to something called default outbound access, which uses a Microsoft managed public IP. While convenient, this approach has some drawbacks. The IP can change without notice and organizations cannot control or monitor the traffic path. Many companies prefer to restrict or explicitly manage outbound traffic through firewalls or NAT solutions.
What Microsoft Is Changing
Beginning March 31, default outbound access will no longer be enabled on new virtual networks. Existing VNets and virtual machines will continue to work as they do today. However, any new virtual network or new subnet will automatically have the private subnet setting enabled. This setting disables default outbound access and requires administrators to create an explicit internet path.
How to Provide Internet Access Going Forward
With default outbound access disabled, you must define your preferred method for outbound connectivity. A NAT Gateway is one of the most common options, but you can also use a firewall, a public IP assigned directly to the VM, or a load balancer depending on your requirements. These services provide predictable outbound IPs and greater control over security and logging. Click here for information on creating a NAT Gateway. (Boost Azure Networking Performance and Resilience with the Standard V2 NAT Gateway)
What You Need to Do
Your existing infrastructure is not affected, but new deployments require attention. If your environment uses automated deployments, such as IaC templates that build VNets, make sure they include a supported outbound path.
If you choose to transition existing subnets into private subnets, the steps are straightforward:
- Ensure an outbound path is configured and working, such as a NAT Gateway.
- Enable the private subnet option on the subnet.
Although it is technically possible to disable the private subnet setting after March 31, Microsoft does not recommend it. The long‑term goal is for all VNets to follow the model of explicit outbound control.
Is This Update Really Happening
Microsoft previously delayed this change, which caused some uncertainty in the community. However, all indications suggest that the March 31 rollout is happening this time. Taking action now ensures your deployments continue to work without interruption.
Final Thoughts
This update moves Azure toward a more secure and predictable networking model. By requiring explicit outbound paths, organizations gain better control of their internet traffic, improve their Network Security posture, and maintain consistent Cloud Networking behavior across VNets. Preparing now will keep your workloads connected and secure as Azure continues to evolve.
If you want a walkthrough of what to expect and how to prepare, be sure to watch the full video linked above.
Links:
Zero to Hero with Azure Virtual Desktop
https://www.udemy.com/course/zero-to-hero-with-windows-virtual-desktop/?referralCode=B2FE49E6FCEE7A7EA8D4
A Beginner’s Guide to the AZ-900
https://www.udemy.com/course/beginners-guide-az-900/?referralCode=C74C266B74E837F86969
Hybrid Identity with Windows AD and Azure AD
https://www.udemy.com/course/hybrid-identity-and-azure-active-directory/?referralCode=7F62C4C6FD05C73ACCC3
Windows 365 Enterprise and Intune Management
https://www.udemy.com/course/windows-365-enterprise-and-intune-management/?referralCode=4A1ED105341D0AA20D2E
Default Outbound Access
https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/default-outbound-access?WT.mc_id=AZ-MVP-5004159
Boost Azure Networking Performance and Resilience with the Standard V2 NAT Gateway
Azure Private Subnets Explained: Disable Default Outbound Access in 2025
