What method of connecting to an Azure VM necessitates that the VM has a public IP address?

Connecting to an Azure VM using a public IP address allows direct access from the internet. A public IP address uniquely identifies the VM on the internet, enabling external traffic to reach it. This method is crucial for scenarios where users or applications outside the Azure cloud need to communicate with the VM, such as accessing a web server or an application running on the VM.

In contrast, other connection methods do not require a public IP for access. For instance, using a VPN establishes a secure tunnel for encrypted connections through a private network, making a public IP unnecessary but often preferable for enhanced security. A Local Area Network typically pertains to access within a specific physical area or organization, while a Site-to-Site connection connects two networks over the internet securely, utilizing IPsec but again bypassing the need for a public IP directly to the VM. Therefore, the direct method of connection that explicitly requires the presence of a public IP address is through the use of that public IP itself.