Which record should you create in the contoso.com DNS domain?

You have a website that uses an FQDN of www.contoso.com. The DNS record tor www.contoso.com resolves to an on-premises web server.

You plan to migrate the website to an Azure web app named Web1. The website on Web1 will be published by using an Azure Front Door instance named ContosoFD1. You build the website on Web1.

You plan to configure ContosoFD1 to publish the website for testing.

When you attempt to configure a custom domain for www.contoso.com on ContosoFD1, you receive the error message shown in the exhibit.

You need to test the website and ContosoFD1 without affecting user access to the on-premises web server.

Which record should you create in the contoso.com DNS domain?
A . a CNAME record that maps www.contoso.com to ContosoFD1.azurefd.net
B . a CNAME record that maps www.contoso.com to Web1.contoso.com
C . a CNAME record that maps afdverify.www.contoso.com to ContosoFD1.azurefd.net
D . a CNAME record that maps afdverify.www.contoso.com to afdverify.ContosoFD1.azurefd.net

View Answer

Answer: C

Explanation:

When configuring an Azure Front Door instance with a custom domain, you typically encounter this issue if you’re trying to add a domain to Azure Front Door that is already in use elsewhere. To avoid affecting user access to the on-premises web server while testing, you would use an afdverify subdomain to test the custom domain configuration with Azure Front Door.

The correct record to create is:

C. a CNAME record that maps afdverify.www.contoso.com to ContosoFD1.azurefd.net

This record allows Azure Front Door to verify the domain without affecting the current DNS setup for www.contoso.com. After verification, you can complete the configuration for the custom domain in Azure Front Door. Once testing is successful and you’re ready to go live, you can then update the CNAME record for www.contoso.com to point to ContosoFD1.azurefd.net, which would direct all traffic to the Azure Front Door instance.