Question

Difficulty: MediumConfigure Azure DNS Private and Public Zones

To support a new internal application architecture, you deploy a virtual network named `VNet-Core` and create two Azure Private DNS zones named `corp.internal` and `services.internal`.

You attempt to create virtual network links from `VNet-Core` to both private DNS zones, enabling the auto-registration setting on both links.

What is the outcome of this configuration?

  1. The second virtual network link will fail to be created because a virtual network can be linked to only one private DNS zone with auto-registration enabled.Answer
  2. B
    Both links will be created successfully, and the virtual machines in `VNet-Core` will automatically register their DNS records in both private DNS zones.
  3. C
    Both links will be created successfully, but the virtual machines in `VNet-Core` will only automatically register their DNS records in the private DNS zone that was linked first.
  4. D
    The configuration will fail because a virtual network can only be linked to a single private DNS zone, regardless of whether auto-registration is enabled.

Answer

The second virtual network link will fail to be created because a virtual network can be linked to only one private DNS zone with auto-registration enabled.
Azure Private DNS allows a virtual network to be linked to multiple private DNS zones for name resolution. However, a virtual network can only be linked to a single private DNS zone with auto-registration enabled. Attempting to enable auto-registration on a second link for the same virtual network will fail during deployment.

Step-by-Step Solution

1
Analyze the requirements for linking a virtual network to multiple Azure Private DNS zones.
A virtual network can be linked to multiple Private DNS zones for name resolution.
Enabling name resolution across multiple zones is a supported scenario.
2
Identify the restriction on the auto-registration feature for virtual network links.
Each virtual network can have at most one link with auto-registration enabled.
Azure enforces this limit to avoid duplicate or conflicting DNS records for a single VM across multiple zones.
3
Evaluate the deployment outcome of configuring two auto-registration links for the same virtual network.
The creation of the second link with auto-registration enabled fails.
The system validates and rejects the second auto-registration link.

Key Concept

Virtual network link limitations in Azure Private DNS
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