The FTP host xxx.ftp.azurewebsites.windows.net no longer resolves in the DNS

Marco Dieleman 5

We cannot connect to our Azure App Services through FTP. We get this error from the FTP client:

Address lookup of "ftp://*****.ftp.azurewebsites.windows.net" failed.

Deepanshu katara 17,875 Reputation points MVP Moderator

2024-06-03T09:24:10.1266667+00:00

Hi Marco ,

I think you may need to enable both SCM basic Auth Credentials and FTP basic Auth Credentials , please check this image for ref , by default they are turned off

By following these steps, you'll be able to enable both SCM (Kudu) basic authentication credentials and FTP basic authentication credentials for your Azure App Service. These credentials allow you to access your App Service for deployment and management purposes using both SCM (Kudu) and FTP protocols.

Also , please check this as it has similar https://learn.microsoft.com/en-us/answers/questions/1638638/how-to-fix-could-not-find-host-waws-prod-blu-xxx-f

For more info , please check these links https://learn.microsoft.com/en-us/azure/app-service/configure-basic-auth-disable?tabs=portal

https://learn.microsoft.com/en-us/azure/app-service/deploy-configure-credentials?tabs=cli

Kindly accept answer if it helps , Thanks
Marco Dieleman 5 Reputation points

2024-06-03T09:36:32.3766667+00:00

Both SCM basic Auth Credentials and FTP basic Auth Credentials are enabled.

We were always able to connect to the Web apps through FTP, but today we discovered we cannot connect to any of the sites on the same App Service Plan.

This is not an issue on our side or in the configuration of the Web app, but it's more likely to be a DNS issue.
Deepanshu katara 17,875 Reputation points MVP Moderator

2024-06-03T09:51:44.73+00:00
Ok then Here are some additional troubleshooting steps you can try:

Check DNS Configuration in Azure Portal: Go to the Azure portal and navigate to your Azure App Service. Check the custom domains and DNS settings configured for your App Service. Ensure that the FTP hostname is correctly configured and pointing to the correct Azure App Service.

Verify Custom Domain Configuration: If you're using a custom domain for your App Service FTP hostname, ensure that the DNS records (e.g., CNAME or A record) for the custom domain are correctly configured to point to the Azure App Service endpoint. You can check that in your DNS provider
Marco Dieleman 5 Reputation points

2024-06-03T10:01:31.0933333+00:00

The issue is not with our custom domain but with the DNS of the FTP host. We can connect to other Web Apps that run on a different App Service Plan and have a different URL to the FTP host.
SnehaAgrawal-MSFT 22,721 Reputation points Moderator

2024-06-04T07:09:50.4733333+00:00

@Marco Dieleman Could you please share which App Service plan and region you have deployed?
Marco Dieleman 5 Reputation points

2024-06-04T07:21:12.1066667+00:00

Hi, I just checked this morning and the problem no longer occurs. I can connect through FTP as I always did and the host can be resolved in the DNS again.

It seems there has been some kind of upgrade or fix from Azure. I can see in our monitoring tool that all our websites were unavailable for a few minutes last night around 9.20pm (CET).
SnehaAgrawal-MSFT 22,721 Reputation points Moderator

2024-06-05T10:54:21.4766667+00:00

@Marco Dieleman Thanks for reply!

It seems there has been some kind of upgrade or fix from Azure. I can see in our monitoring tool that all our websites were unavailable for a few minutes last night around 9.20pm (CET)

Could you please check Service Health and Resource Health status for more information

Azure Service Health provides you with a customizable dashboard which tracks the health of your Azure services in the regions where you use them Azure Resource Health helps you diagnose and get support for service problems that affect your Azure resources.

It reports on the current and past health of your resources.

Your answer