Azure.RequestFailedException: No such host is known - azure

Question

I have an application (aspnet core app 3.1) where I load data during startup from azure blob storage with the following code:
BlobClient client = new BlobClient(loaderOptions.ConnectionString, loaderOptions.BlobContainerName, loaderOptions.BlobName);
var response = client.Download();
using (var memoryStream = new MemoryStream())
{
response.Value.Content.CopyTo(memoryStream);
return memoryStream.ToArray();
}
Locally, on my PC everything works fine. But when I publish this app to azure app service (windows) I get the following errors:
Unhandled exception. System.AggregateException: Retry failed after 6 tries. (No such host is known.) (No such host is known.) (No such host is known.) (No such host is known.) (No such host is known.) (No such host is known.)
---> Azure.RequestFailedException: No such host is known.
---> System.Net.Http.HttpRequestException: No such host is known.
---> System.Net.Sockets.SocketException (11001): No such host is known.
at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
--- End of inner exception stack trace ---
at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean allowHttp2, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.GetHttpConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message)
--- End of inner exception stack trace ---
A week ago everything worked fine. Now I have created new service plans and storage accounts (deleted old ones) and come across this problem.
What can be solution?

Answer 1

I am experiencing the same issue as this. Further analysis would indicate, Local DNS issues. If in doubt trace the address supplied and where needed add a temporary host record in c:\windows