Custom Domain on App Service not validating even after DNS entries confirmed by multiple tools

Question

Attempting to add a custom Domain to an App Service.

I have ensured that the CName and TXT record provided in the UI while adding the custom domain have been added.

I have verified using external tools and the cloud shell within the Azure portal - and all show that the DNS entries are present.

When I attempt to validate the domain on the app service however it says it cannot find the DNS records.

It has been over 24 hours, so I don't believe propagation is the issue here.

I also had another custom domain, added to a different App Service, and that validated much more quickly; so there just appears to be an issue with this one combo.

Any suggestions are appreciated!

Answer 1

Hi @Matt Charron
Kindly ensure that the CNAME record points to your app's default domain (appname.azurewebsites.net) and that the TXT record follows the exact format specified by Azure.
Use App Service Diagnostics in the Azure Portal under "Diagnose and Solve Problems" > "Availability and Performance" to identify issues. You mentioned that 24 hours have passed, which should be sufficient for DNS propagation.

However, in rare cases, some DNS servers take longer to update.
Confirm your App Service Plan is at least Basic tier, as Free/Shared tiers don’t support custom domains.
Sometimes, Azure's validation service takes longer to recognize DNS changes, even when external DNS resolution works fine. Try re-entering the domain or reinitiating the validation process.
references:https://learn.microsoft.com/en-us/answers/questions/699662/unable-to-verify-domain-name-in-azure-app-services