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Azure Front Door (classic) and CDN Standard from Microsoft (classic) migration FAQ

Applies to: ✔️ Front Door (classic) ✔️ CDN Standard from Microsoft (classic)

This article provides answers to frequently asked questions about migrating from Azure Front Door (classic) and CDN Standard from Microsoft (classic) to Front Door Standard or Premium.

Important

Azure Front Door (classic) retires on March 31, 2027. Because the service is retiring, it no longer supports profile creation, new domain onboarding, or managed certificates. To avoid service disruption, ⁠migrate to Azure Front Door Standard or Premium. For more information, see ⁠Azure Front Door (classic) retirement.

Important

Azure CDN Standard from Microsoft (classic) retires on September 30, 2027. Because the service is retiring, it no longer supports profile creation, new domain onboarding, or managed certificates. To avoid service disruption, ⁠migrate to Azure Front Door Standard or Premium. For more information, see ⁠Azure CDN Standard from Microsoft (classic) retirement.

Does the migration cause any downtime?

No, the migration process doesn't cause any downtime. It's a control plane-only migration, so traffic delivery isn't affected.

During migration, the Azure Front Door (classic) endpoint mydomain.azurefd.net is created as a dummy custom domain on Front Door standard or premium. Both classic endpoint and standard or premium endpoints point to the same Front Door IP, so the final resolution stays the same before and after DNS propagation. The endpoint keeps receiving traffic until you update the DNS record of the Front Door custom domain www.mydomain.com to mydomain.randomstring.z01.azurefd.net directly. Change the CNAME from classic endpoint to Front Door standard or premium endpoint after verification.

Even in rare cases where the migration fails, traffic delivery continues to work as expected.

The migration process doesn't support rollback. If migration fails, contact the support team for help.

What should I do after migration?

After migration, follow these steps:

  1. Verify that traffic delivery continues to work.

  2. Update the DNS CNAME record for your custom domain to point to the Front Door Standard or Premium endpoint exampledomain-hash.z01.azurefd.net instead of the classic endpoint (exampledomain.azurefd.net for Front Door (classic) or exampledomain.azureedge.net). Wait for the DNS update to propagate until DNS TTL expires, depending on how long TTL is configured on DNS provider.

  3. Verify again that traffic works in the custom domain.

  4. Once confirmed, delete the pseudo custom domain (that is, the classic endpoint that was pointing to the Front Door Standard or Premium endpoint) from the Front Door Standard or Premium profile.

  5. Then delete the classic resource. 

When I change my DNS CNAME from Front Door (classic) endpoint to Front Door Standard/Premium endpoint, does DNS propagation cause downtime?

No, both classic endpoint and Standard/Premium endpoints point to the same IP, so the final resolution remains the same before and after DNS propagation.

When would the classic endpoint stop working?

Starting April 1, 2028, classic endpoints are no longer supported and might stop functioning. Custom domains, applications, or clients that still depend on a classic endpoint might stop receiving traffic. You must complete the following post-migration action depending on your scenario by March 31, 2028:

  • Custom domains: Update the DNS record to point to the new Azure Front Door Standard/Premium endpoint.

  • Direct use of the classic default endpoint: Replace the classic hostname with the new endpoint hostname in your applications, clients, and integrations.

Both endpoints remain functional during the transition, so you can make and validate this change without downtime.

When should I delete the classic tier?

For Front Door (classic): After verifying that traffic works and the DNS record is updated to point to the Front Door Standard or Premium endpoint, you can safely delete the classic resource.

For CDN Standard from Microsoft (classic): You don't need to delete the classic resource. Migration is treated as a tier upgrade, and the classic resource can remain.

Do I need to update my DevOps pipeline?

Yes. After migration, make sure to update your DevOps pipeline to reflect the new Front Door Standard or Premium configuration and endpoints. Learn more.

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