We are facing issues with Azure Front Door (AFD) configuration in the following scenarios

Question

Hi Team,

We are facing issues with Azure Front Door (AFD) configuration in the following scenarios:

Scenario 1:

• The customer has a VM hosting their application exposed via IIS.
• The subdomain rhino.micology.com is bound to IIS.
• They configured AFD with the VM's public IP as the origin and enabled SSL validation.
• Due to SSL being enforced on both the VM and AFD, they are unable to connect to the origin.
• If SSL validation is disabled, it works, but the customer does not want to disable it for security reasons.

Scenario 2:

• The customer created a separate subdomain for the VM and configured AFD's origin host name to point to this subdomain.
• The application is accessible via AFD, but application-side changes are required, which is causing challenges.

Could you please advise on the possible and non-possible solutions from the AFD side to ensure a secure and functional setup?Hi Team,

Answer 1

Hello Avinash

Greetings!

I understand that you are facing issues with Azure Front Door (AFD) configuration.

You have an AFD, and the backend IIS is hosted in the VM.

Please check the front door origin group. In the Hostname field, add the VM public IP, and in the host header field, configure the backend host header name.

To enable HTTPS in the front door, configure a custom domain and add the certificate properly. Also, configure the same hostname and bundle the same certificate in the backend.

If you want to use a different hostname in the backend, add the backend host header in the AFD origin group properly and remove the certificate namecheck in the front door.

Check the below screen shot for more understanding:

Check the public document for more understanding:

https://learn.microsoft.com/en-us/azure/frontdoor/troubleshoot-issues#503-responses-from-azure-front-door-only-for-https

And also check the below public document how to add custom domain in Front door:

Add a new custom domain

You can also collect the tracking reference ID in the access logs when encountering the issue. Use this reference ID to check logs in your Azure portal. Please refer to the following document for collecting the logs:

https://learn.microsoft.com/en-us/azure/frontdoor/refstring?source=recommendations&tabs=edge

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