Your company needs to ensure that in Azure virtual machine can connect to Azure SQL databases without exposing the databases to the internet. What should you use?

Azure Private Link provides private connectivity from a virtual network to Azure PaaS services, such as Azure SQL Database. It achieves this by creating a private endpoint, which is a network interface that uses a private IP address from your virtual network. This effectively brings the Azure SQL Database service into your private network. Consequently, all traffic between the virtual machine in your VNet and the Azure SQL Database travels over the Microsoft backbone network, never traversing the public internet. This directly meets the requirement of ensuring a secure connection without public exposure.

A. Azure DNS: This is a hosting service for DNS domains. While it resolves the private endpoint's name, it does not create the private connection itself.
B. Azure Application Gateway: This is a web traffic load balancer (Layer 7) and is not the appropriate service for securing database connections at the network level.
D. Azure Traffic Manager: This is a DNS-based traffic load balancer that directs traffic to public endpoints and does not provide private network connectivity.

1. Microsoft Learn. "What is Azure Private Link?". Azure Private Link documentation. In the "Key benefits" section, it states, "Access services on the Azure platform privately: Connect your virtual network to services in Azure without a public IP address at the source or destination."

2. Microsoft Learn. "Private Link for Azure SQL Database and Azure Synapse Analytics". Azure SQL Database documentation. The "How it works" section explains, "Private Link allows you to connect to various PaaS services in Azure via a private endpoint... Traffic between your virtual network and the service travels across the Microsoft backbone network."

3. Microsoft Learn. "What is Azure DNS?". Azure DNS documentation. The introduction clearly defines its role: "Azure DNS is a hosting service for DNS domains that provides name resolution by using Microsoft Azure infrastructure." This confirms it is for name resolution, not private connectivity.

4. Microsoft Learn. "What is Azure Traffic Manager?". Azure Traffic Manager documentation. The overview states, "Azure Traffic Manager is a DNS-based traffic load balancer. This service allows you to distribute traffic to your public facing applications across the global Azure regions." This highlights its use for public, not private, endpoints.