📌Empowering Connectivity: Navigating Outbound Access for New Azure VMs with Microsoft's Explicit Methods📢

Default outbound access for VMs in Azure will be retired on 30th September 2025

As organizations evolve in their cloud journey, Microsoft introduces a pivotal shift in outbound access for Azure Virtual Machines (VMs). The directive is clear: all new VMs requiring internet access must utilize explicit outbound connectivity methods. In this blog post, we'll delve into Microsoft's explicit methods—Azure NAT Gateway, Azure Load Balancer outbound rules, and directly attached Azure public IP addresses—to ensure seamless and secure internet connectivity for your Azure VMs.

Understanding the Transition:

The move towards explicit outbound connectivity methods signifies a strategic shift in how Azure VMs access the internet. Instead of relying on default outbound access, organizations are encouraged to adopt specific mechanisms that provide greater control and security.

In Azure, virtual machines created within a virtual network without an explicitly defined outbound method are assigned a default public IP address to facilitate internet connectivity. While existing VMs using the default outbound access will remain operational after this retirement, it is strongly advised to shift towards an explicit outbound method.

This transition ensures that your workloads remain unaffected by public IP address changes, grants greater control over how VMs connect to the internet, and allows the use of traceable IP resources owned by you. If you deploy VMs on Azure Cloud Services (extended support), this retirement will not impact you, and no action is required. This retirement will not impact for all VMs in subnets created after September 2025.

Microsoft's Explicit Outbound Connectivity Methods:

1. Azure NAT Gateway:

   • Purpose: Azure NAT Gateway allows multiple private VMs to share a public IP address for outbound internet connectivity.
   • Implementation: Configure and deploy Azure NAT Gateway to enable outbound communication for VMs while maintaining a centralized and managed public IP address.

2. Azure Load Balancer Outbound Rules:

   • Purpose: Outbound rules on Azure Load Balancer enable VMs to share a public IP address for outbound connectivity.
   • Implementation: Define outbound rules within Azure Load Balancer, specifying the range of ports and protocols required for outbound traffic.

3. Directly Attached Azure Public IP Address:

• Purpose: Assign a dedicated Azure public IP address directly to a VM for exclusive outbound connectivity.
• Implementation: Attach a public IP address to the VM interface, providing a direct and individualized connection to the internet.

Private Subnet parameter:

When you configure a subnet as "Private" in Azure, it restricts virtual machines within that subnet from using default outbound access to connect to public endpoints. It's essential to note that the option to designate a subnet as "Private" can only be set at the time of subnet creation.

Despite being labeled as a "Private" subnet, virtual machines within it still have the ability to access the Internet by utilizing explicit outbound connectivity. This approach allows for controlled and intentional outbound communication from VMs in the specified subnet to public endpoints.

Advantages of Explicit Outbound Connectivity:

1. Enhanced Control: Explicit methods offer granular control over outbound connections, allowing organizations to define specific rules and policies.

2. Improved Security Posture: By adopting explicit methods, organizations can reduce the attack surface and mitigate potential security risks associated with default outbound access.

3. Resource Optimization: Centralized management through Azure NAT Gateway or Load Balancer results in more efficient resource utilization, reducing redundancy.

4. Scalability: Explicit methods provide scalable solutions, accommodating the growing needs of organizations while maintaining optimal performance.

Transitioning to Explicit Outbound Connectivity:

1. Assessment:

   • Evaluate existing VMs and identify those that require internet access.
   • Determine the appropriate explicit outbound connectivity method based on the specific needs of each VM.

2. Deployment:

   • Implement Azure NAT Gateway, Azure Load Balancer outbound rules, or directly attach a public IP address as per the chosen method.
   • Configure rules and settings to align with security and compliance requirements.

3. Communication:

   • Communicate the transition plan to relevant stakeholders, including IT teams, application owners, and end-users.
   • Provide necessary training and support to ensure a smooth adaptation to the new connectivity model.

4. Monitoring and Optimization:

• Implement monitoring tools such as Azure Monitor to track outbound traffic and identify any anomalies.
• Continuously optimize rules and settings to adapt to changing organizational needs.

Conclusion: Microsoft's directive towards explicit outbound connectivity methods for new Azure VMs heralds a new era of control and security in cloud environments. By adopting Azure NAT Gateway, Azure Load Balancer outbound rules, or directly attached public IP addresses, organizations can ensure a robust and scalable approach to outbound internet connectivity. As you navigate this transition, consider the unique requirements of your workloads and leverage the flexibility provided by these explicit methods to empower your Azure VMs with secure and efficient internet access.