WebApp custom DNS resolution through Point to Site to a VNET

Question

Hi,
I have an App Service connected to a virtual Network through Point to site VPN.
My App Service can access my On-Premise ressources via Virtual Network Gateway and Site to Site VPN.

Is there a way for my App Service to resolve On-Premise DNS Records by using On-Premise DNS servers?

I've tried to add custom DNS servers in VNET configuration, but it is not working.

Thank you for your help,

BR
Thomas.

Answer 1

Thanks for asking question and My Apologize for delay in response here! After your app integrates with your VNet, it uses the same DNS server that your VNet is configured with. By default, your app won't work with Azure DNS Private Zones. To work with Azure DNS Private Zones you need to add the following app settings:

1. WEBSITE_DNS_SERVER with value 168.63.129.16
2. WEBSITE_VNET_ROUTE_ALL with value 1
   These settings will send all of your outbound calls from your app into your VNet in addition to enabling your app to use Azure DNS private zones.

If you want to make calls to Private Endpoints then you need to either integrate with Azure DNS Private Zones or manage the private endpoint in the DNS server used by your app.