AZ-104 Question 184
Single answerYou are an Azure Administrator for a retail company. The marketing team wants to map the custom domain name 'www.contoso.com' to the existing Azure App Service web app named 'contosoweb.azurewebsites.net'. You have added the custom domain in the Azure portal, but the verification step fails. Which action must be taken within your DNS provider to verify domain ownership for the subdomain?
- A
Create a CNAME record for www.contoso.com that points to contosoweb.azurewebsites.net
- B
Create an A record for www.contoso.com that points to the App Service’s IP address
- C
Add a TXT record with a unique token from the certificate authority
- D
Set a custom domain certificate in the Azure App Service
Show answer and explanation
Correct answer: A
Explanation
Mapping a subdomain (www) to an Azure App Service requires creating a CNAME record in your DNS to establish domain ownership. Once the DNS record is in place and propagates, the Azure portal will confirm ownership, and the custom domain will successfully map to the App Service.
- A. Correct.
Correct. For subdomains, you must create a CNAME record mapping the custom DNS name to the default hostname of the App Service to verify ownership.
- B. Incorrect.
An A record is typically required only when mapping a root (apex) domain, not a subdomain like 'www'.
- C. Incorrect.
While some domain verifications use TXT records, in this specific scenario with a subdomain, a CNAME record to the App Service’s default domain is required to verify ownership.
- D. Incorrect.
Configuring a custom certificate in Azure is a separate step from verifying domain ownership. It does not replace the DNS record requirement.