Validating Sub-domain

Question

Hello, I am attempting to add a pre-owned custom domain to my web app service. THe custom domain is actually a sub-domain and is blog.wellrabbit.com. When I attempt to validate the domain or to update my dns records from my domain provider, I am still forwarded to a 404 page and the domain never validates.

Answer 1

@Anthony Benjamin-WR-server We are sorry to hear that you are encountering 404 errors when trying to add your custom sub-domain to your web app.

Can you please provide us with context as to how you are validating your sub-domain? Are you using an A record, CNAME, and how are you entering the domain name into Azure?

Please note that it can take up to 30+ minutes for the DNS propagation to take effect. For this reason, we do not recommend performing the switch during business hours to minimize customer impact. Can you verify that you waited the appropriate amount of time?

Please note that we recommend using CNAME records for domain validation. Please see the below settings to ensure you were putting in the correct items into your DNS.

Step 1: Add a CNAME record type to your DNS with a host setting of blog and a value of <app-name>.azurewebsites.net
Steps 2: Add a TXT record type to your DNS with a host setting of asuid.blog and a value of the verification ID you got from the custom domains blade of your web app in the Azure portal. This step is very important as adding the verification ID helps to prevent a security issue called dangling DNS.

For more information on this, please see here:

• Tutorial: Map an existing custom DNS name to Azure App Service
• Prevent dangling DNS entries and avoid subdomain takeover