In every project where I’m involved, I always try to follow Azure best practices, one of them is to set a custom DNS Server in Azure VNets. Why? The answer is easy:
Have you deployed a a VNet in a subscription? If yes, continue reading. Have you deployed a Dc with DNS inside this VNet? If yes, continue reading… Have you deployed other VM’s in this VNet, and did you need to configure the DNS server manually in each of this machines?
Probably you have faced this scenario at some point in Azure, so in order to avoid the manual configurations in the properties of every server, you can configure the DNS settings at VNet level.
With this, you will be following Azure Best Practices and every server in this VNet will inherit the properties. The only thing that you will need to do is to restart the servers that exist in this VNet to inherit the new properties.
New servers deployed into the VNet, will inherit the properties by default, so will be easy yo configure them in case is it necessary.
Till next time!