I've been asked a question by the boss and actually I can't find any sort of coherent / comprehensive answer out there!
So I turn to you, the wise and all-knowing collective of StackOverflow :)
The question of the day is "Does .NET support transport layer security version 1.1 or 1.2?" Google is next to useless on this issue and the documentation out there is severely lacking.
Any help on this would be greatly appreciated.
Thank you, Clint
TLS 1.1 and 1.2 support has been added to Windows 7 and my understanding is that .NET relies on Windows' SChannel for TLS support. So I think the answer to your question is "depends on the OS".
Now you should remember, that most sites are powered by older versions of OpenSSL and other libraries which not just didn't support TLS 1.1 and 1.2, but closed connection immediately if they received indication of TLS 1.1 support from the client. In other words, if you enable TLS 1.1 support in your client, you won't be able to connect to some of servers.
Upd: Forgot to mention that you can use third-party SSL/TLS implementation (eg. the one in our SecureBlackbox product) to get TLS 1.x support in your .NET application.