CDN endpoint - cannot set custom domain

60856927 26

When I try to add custom domain to CDN endpoint, is says: "We couldn't find a DNS record for 'ogl.app' that points to 'oglapp.azureedge.net'. Before you can associate a domain with this CDN endpoint, you need to create a CNAME record with your DNS provider for 'ogl.app' that points to 'oglapp.azureedge.net'." But CNAME set properly. https://toolbox.googleapps.com/apps/dig/#CNAME/ What is wrong?

Ganeshkumar R 590 Reputation points

2024-07-04T18:06:53.9633333+00:00
When setting up a custom domain for your Azure Content Delivery Network (CDN) endpoint and encountering issues with DNS validation, there are several potential factors to consider. Here's a step-by-step guide to troubleshoot and resolve the issue:

Step-by-Step Troubleshooting

Verify CNAME Record

Use DNS lookup tools to verify that the CNAME record is correctly set up.

For example, using the Google Dig tool: Google Dig Tool

Ensure that the CNAME record for ogl.app points to oglapp.azureedge.net.

CNAME record for ogl.app: ogl.app. IN CNAME oglapp.azureedge.net.

DNS Propagation

DNS changes can take some time to propagate. It might take up to 48 hours for DNS records to fully propagate across all DNS servers.

Use multiple DNS lookup tools to confirm the CNAME record:

DNS Checker

WhatsMyDNS

Check DNS propagation globally to ensure the CNAME record is available worldwide.

Cache and TTL (Time-To-Live)

Clear your DNS cache to ensure you're not seeing outdated DNS information.

You can clear the DNS cache on your local machine with the following commands:

Windows: ipconfig /flushdns

macOS: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Linux: sudo systemd-resolve --flush-caches

Check the TTL value of your DNS record. If the TTL is high, it might take longer for changes to be recognized.

Correct DNS Configuration

Ensure that the CNAME record is correctly configured in your DNS provider's control panel.

Double-check for typos or incorrect values.

Custom Domain Validation in Azure

Navigate to the Azure portal: Azure Portal.

Go to your CDN profile and select the CDN endpoint.

Under the Custom domains section, try adding the custom domain again.

Azure will perform a DNS check to verify the CNAME record.

Check for DNSSEC

If your domain is using DNSSEC (DNS Security Extensions), ensure that it is configured correctly. DNSSEC misconfigurations can sometimes cause issues with DNS resolution.

Using Azure CLI for Validation

You can use Azure CLI to check the custom domain validation status. Run the following command:

az cdn custom-domain validate --profile-name <CDN_Profile_Name> --endpoint-name <CDN_Endpoint_Name> --hostname ogl.app --resource-group <Resource_Group_Name>
Replace <CDN_Profile_Name>, <CDN_Endpoint_Name>, and <Resource_Group_Name> with your actual resource names.

Example DNS Lookup Check

Using the Google Dig tool, you should see an output similar to this if the CNAME is correctly set:

; <<>> DiG 9.10.6 <<>> CNAME ogl.app ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12345 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1 ;; QUESTION SECTION: ;ogl.app. IN CNAME ;; ANSWER SECTION: ogl.app. 3600 IN CNAME oglapp.azureedge.net. ;; AUTHORITY SECTION: azureedge.net. 3600 IN NS ns1-azureedge.net. azureedge.net. 3600 IN NS ns2-azureedge.net. ;; ADDITIONAL SECTION: ns1-azureedge.net. 3600 IN A 104.40.175.65 ;; Query time: 100 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Thu Oct 14 12:34:56 UTC 2023 ;; MSG SIZE rcvd: 123

If you have followed all these steps and are still encountering issues, contacting Azure support for further assistance would be a prudent next step.
60856927 26 Reputation points

2024-07-04T19:56:59.66+00:00

All looks correctly set but endpoint still says cname is not set.
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Accepted answer

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-05T15:29:47.85+00:00
@60856927 ,

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

Can you confirm if the CDN SKU is Microsoft? Or is it Azure CDN Standard from Edgio/ Azure CDN Premium from Edgio?

Can you confirm if the CDN's endpoint is actually "oglapp.azureedge.net" and not something else?

Can you share a screenshot of the error message please?

Cheers,

Kapil
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60856927 26 Reputation points

2024-07-05T19:13:16.6233333+00:00

It is Azure CDN Standard from Edgio. I tried Microsoft CDN classic as well, result was the same. I noticed I can set host of www in CNAME config and www.ogl.app can be assigned successfully to Azure CDN, but I want ogl.app without www prefix. Is it possible?
Here is the screenshot where you can see all the endpoint info and the error:
https://imgur.com/a/DxI92WY

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-08T11:04:08.2166667+00:00

@60856927 ,

Wrt, "I noticed I can set host of www in CNAME config and www.ogl.app can be assigned successfully to Azure CDN, but I want ogl.app without www prefix. Is it possible?"

Yes, this is possible

See : Onboard a root or apex domain to Azure CDN

As next steps,

I don't see "ogl.app" having a CNAME record pointing to any domain

Is this intentional? Did you make any recent changes?

I would suggest you to please give this another try and let me know how it goes with CDN

Cheers,

Kapil

60856927 26 Reputation points

2024-07-08T18:50:00.04+00:00

@KapilAnanth-MSFT , yes, I removed CNAME for ogl.app that pointed to oglapp.azureedge.net because it doesn't work.
Thank you for the link to the guide but it is unclear where can I find "Azure DNS". No such a service shown in Azure portal search.

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-10T06:09:33.4033333+00:00

@60856927 ,

Using Azure DNS is not mandatory.

However, you can host your domain in Azure using Azure DNS Service.

Despite whether or not the DNS is hosted in Azure, you should be able to verify and add the domain to CDN provided the CNAME(Alias) is correct.

See : https://www.digwebinterface.com/?hostnames=ogl.app&type=&useresolver=9.9.9.10&ns=self&nameservers=1.1.1.1

Can you please revert back to adding a CNAME(Alias) record for "ogl.app" pointing to "oglapp.azureedge.net" and try once again in CDN?

And let me know if this helped?

In case this does not help,

We will need a specialized 1:1 session, where a support engineer can have a screen share session to pinpoint the issue.

If you have a support plan you may file a support ticket, else please do let us know, we will try and help you get a one-time free technical support.

Cheers,

Kapil

60856927 26 Reputation points

2024-07-12T20:41:32.4666667+00:00

, tried again, it doesn't work. Unfortunately I do not have support plan. And it is weird that I have to pay for support with the thing that should work. The error message is wrong because the CNAME is set correctly.

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-15T05:55:39.4333333+00:00

@60856927 ,

To troubleshoot further, we will need a specialized 1:1 session, where a support engineer can have a screen share session to pinpoint the issue. If you have a support plan you may file a support ticket, else please do let us know, we will try and help you get a one-time free technical support.

Cheers,

Kapil

60856927 26 Reputation points

2024-07-15T19:00:09.34+00:00

, unfortunately support engineer cannot solve the issue. Azure CDN error message is wrong when it says that CNAME is not configured properly. Azure CDN doesn't support setting root domain as custom domain. To set root domain as custom domain requires to use Azure Front Door service that is robust and expensive. I don't need all the Front Door features. I need what CDN provides, but as I wrote above, Azure CDN doesn't support setting the root domain as custom domain and it writes wrong error message about unconfigured CNAME. I will set the root domain to my Web App. It is also not so cheap but at least I get better performance for the same money like paying for Front Door.

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-17T08:14:28.7133333+00:00

@60856927 ,

From the document : Onboard a root or apex domain to Azure CDN, you should be able to onboard an apex/root domain for CDN.

Please continue to work with Azure Support to get this issue resolved.

KapilAnanth-MSFT 41,156 Reputation points Microsoft Employee

2024-07-24T11:33:17.5966667+00:00

@60856927 ,

Post working with Azure Support we found that

Adding a "cdnverify" -------> "cdnverify.oglapp.azureedge.net" (CNAME) record is needed before adding the custom domain

So, essentially, we need two records

cdnverify -------------> cdnverify.oglapp.azureedge.net (CNAME)

@ ---------------------> oglapp.azureedge.net (CNAME at Apex Level)

Once the above record has been added, you confirmed you were able to add your custom domain to the Azure CDN EndPoint.

Note : To enable HTTPS on an Azure CDN custom "Apex" domain, you must use the Bring your own certificate feature.

Cheers,

Kapil
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CDN endpoint - cannot set custom domain

Step-by-Step Troubleshooting

Example DNS Lookup Check

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