Designing and Implementing Microsoft DevOps Solutions (AZ-400) 2025 – The All-in-One Guide to Master Your Exam Success!

To prevent users of VM1 and VM2 from accessing websites on the Internet, associating the Network Security Group (NSG) to Subnet1 is an effective solution because it allows you to control the network traffic flow at the subnet level. By placing the NSG at the subnet level, any virtual machines within that subnet inherit the security rules defined in the NSG, including any rules that can deny or allow outbound Internet traffic.

When you set rules in the NSG to deny outbound access to specific ports or IP addresses—which includes those typically used for web traffic—the rules apply not only to the individual VMs but to all resources residing in that subnet. Thus, by associating the NSG with Subnet1 and configuring the appropriate outbound security rules, you effectively block all users on VM1 and VM2 from reaching websites on the Internet, ensuring that outbound traffic is restricted based on your organization's policy requirements.

This approach is preferable in scenarios where multiple VMs require the same set of security restrictions, allowing for easier management and maintenance of security settings across the resources in that subnet.