.Net Framework 4.6.1 not defaulting to TLS 1.2

Question

Our client have recently upgrade the security protocol to TLS 1.2. Therefore We have our application upgraded to 4.6.1 expecting the security protocol will be default to TLS

Answer 1

Based on the following link

https://docs.microsoft.com/en-us/dotnet/framework/network-programming/tls

I've added

AppContext.SetSwitch("Switch.System.Net.DontEnableSystemDefaultTlsVersions", false);

to my code, and this fixed the issue for me. This is meant to default to the highest level the OS supports, which is the same behaviour you get by default from 4.7 and above.