Unable to read data from the transport connection: A connection attempt failed because the connected party

Question

I am calling Logic App from Azure Function App using HttpClient call. Till yesterday Logic App and Function App both worked fine. But today, function app unable to call logic app.

I got below error in Function app

System.Net.Sockets.SocketException

The SSL connection could not be established, see inner exception. Unable to read data from the transport connection: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

When I test function app locally, it executed successfully and called logic app aswell without any issues. Getting issue only post deployment.

Kindly suggest.

Answer 1

I had similar problem when my application had no security protocol defined. Then I had to switch my application to use TLS 1.2. Now a days servers are turning older protocols off.

If you are having the same problem then you can define a protocol by simply adding the following like to the Application_Start method in your Global.asax.cs file:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;