Exploring Azure Private DNS

This post explores Azure’s Private DNS service and some example scenarios for deploying it within your infrastructure.

Azure provides internal DNS resolution for VM’s and services that reside within the same virtual network (VNET).

For non-Active Directory joined services, an internal DNS suffix called *.internal.cloudapp.net is automatically created and managed by Azure. For example, if you’ve deployed an HDInsight cluster, you’ll notice you’ll have similar hosts to the following -

This capability works well and doesn’t require any specific configuration. Initially, this is enough to get most people going within Azure and allows services to talk to each other.

However, once you start deploying services across VNET’s common challenges include -

• DNS resolution for services that are only accessible via private IP addresses
• How to handle name resolution between virtual networks

Previously in Azure, this would have meant standing up your own custom DNS solution, i.e. BIND running on Linux VMs as shown below -