Azure Private DNS Zone Names and Configuration Best Practices

Naming your Azure Private DNS Zone is a crucial step in its configuration.

Choose a name that is unique and follows the DNS naming convention, which is a series of labels separated by dots.

Avoid using underscores in your zone name, as it can lead to issues with DNS resolution.

Keep your zone name short and descriptive, making it easier to manage and troubleshoot.

Creating an Azure Zone is a straightforward process that involves creating a resource group, private DNS zones, and DNS A records.

To start, you need to create a resource group in Azure, which serves as a logical container for resources deployed on Azure.

A resource group in Azure can be created using a Terraform configuration file, specifically the main.tf file. This file contains the necessary code to create the resource group with a given name and location.

Private DNS zones can also be created using the main.tf file, and it's done using the for_each construct to create multiple DNS zones based on the dns_zones variable.

To create DNS A records, you'll need to add another block to the main.tf file, again using the for_each construct to create multiple DNS records based on the dns_records variable.

To create an Azure DNS Private zone using Terraform, you'll need to define a resource group in your main.tf file. This logical container holds all the resources deployed on Azure.

A resource group in Azure can be created with a given name and location. The location is crucial as it determines where your resources will be stored.

You'll also need to create private DNS zones using Terraform. This is done with the for_each construct, which allows you to create multiple DNS zones based on a variable called dns_zones.

The main.tf file will contain a block for creating DNS A records, which is another essential component of your Azure DNS Private zone. The for_each construct is used again to create multiple DNS records based on a variable called dns_records.

Here are the key components you'll need to create an Azure DNS Private zone using Terraform:

Creating an Azure Zone can be a bit tricky, especially when it comes to setting up Private Endpoint DNS name resolution over point to site (P2S) VPN connections.

To start, you'll need to understand that Azure Virtual Network VPN Gateway or Virtual WAN VPN Gateway are key components in making this work.

Using a DNS forwarder is a viable solution for resolving private DNS zones when connected to a VPN, but it's not the best option available.

In fact, a better solution exists, which is what we'll be exploring in this article.

Zone Configuration is a crucial part of setting up Azure Private DNS zones. You can specify the names of the private DNS zones to be created using the dns_zones variable, which is a list of objects.

This variable can be used to create multiple private DNS zones with different names. For example, if you want to create private DNS zones for different departments or teams within your organization.

Here are the possible settings for the dns_zones variable:

Input Variables are a crucial part of Zone Configuration.

In Terraform, variables are defined in a separate file called variables.tf, allowing for more flexibility and reusability in the code. This file is where you declare the input variables that will be used in the main.tf file.

The tags variable is a map of strings that allows you to assign tags to Azure resources being created. For example, you can use a key-value pair such as Terraform = true.

The resource_group variable is a map that should include the name and location keys.

You can specify the names of the private DNS zones to be created using the dns_zones variable, which is a list of objects.

To specify the settings for the DNS records to be created, use the dns_records variable, which is also a list of objects.

Here's a summary of the variables we've discussed:

Zones are the foundation of a private DNS setup. They allow you to resolve names for resources in a private network.

A Private DNS Zone is created in the main.tf file, which is a key component for Azure private zone deployment. Resource groups, private DNS zones, and DNS A records are the main components of this file.

Private DNS Zones enable you to resolve names for resources in a private network. This is achieved through the use of records that are only resolvable from within a linked VNet and not from the outside.

There are several benefits to using Private DNS Zones, including the ability to work across regions and link to multiple VNets at the same time. They are also resilient to regional outages, as records are replicated across regions.

Here are the key features of Private DNS Zones:

Private DNS Zones also offer an auto registration feature, which allows you to register the names of virtual machines in a Private DNS Zone automatically. However, there are some minor limitations to keep in mind, such as not being able to delegate subdomains to other Private DNS Zones, or certain zone names being restricted.

Azure Private DNS zone names must be unique within a subscription, so if you're getting an error message saying that the name already exists, try renaming your zone to something unique.

If you're experiencing issues with DNS resolution, check that your Private DNS zone is properly configured and that the name servers are correctly set up.

The maximum length of an Azure Private DNS zone name is 64 characters, so keep your name concise and easy to manage.

P2S VPN clients can't resolve Private Endpoint entries hosted on Azure Private DNS Zones, but there's a solution.

One solution is to use a DNS Forwarder, which can redirect DNS queries to Azure DNS.

A DNS Forwarder can be hosted on a virtual machine or a container service like ACI or AKS.

The setup is relatively straightforward, as you only need to forward queries to the Azure DNS IP: 168.63.129.16.

Configuring a DNS forwarder is a bit more involved than other solutions, but it's still a viable option.

Using a DNS Forwarder is the recommended solution for resolving private DNS zones, and it works well.

However, there are some inconveniences with this approach, such as requiring proper setup and maintenance.

The DNS forwarder or proxy becomes an additional piece of software that needs to be managed, which can be a challenge.

If you use a virtual machine instead of a containerized approach, you'll need to manage the underlying OS updates, which can be time-consuming.

Setting the DNS forwarder as the main DNS server for the VNET implies a need for high availability deployment, which can be complex.

A DNS Forwarder is a solution for P2S VPN clients to resolve Private Endpoint entries hosted on Azure Private DNS Zones. It's a relatively straightforward setup that requires forwarding queries to the Azure DNS IP: 168.63.129.16.

You can deploy a DNS forwarder on a virtual machine or a container service like ACI or AKS. It's recommended to use a containerized approach for easier maintenance.

The DNS forwarder can be configured to forward queries to Azure DNS, allowing P2S VPN clients to resolve Private Endpoint entries. This setup works well and is the recommended solution for resolving private DNS zones.

However, it's worth noting that the DNS forwarder becomes an additional piece of software that requires proper setup and maintenance. This can be more challenging if you use a virtual machine instead of a containerized approach.

Here are some benefits of using a DNS forwarder:

You can refer to the GitHub Repository - az-dns-forwarder for more information on setting up a DNS forwarder.