So, I had occasion to try and connect to a windows machine from my Mac. As a long time windows user, my default goto for this is of course Microsoft’s Remote Desktop Protocol. And as luck would have it, OS X/macOS ships with a client called Remote Desktop Connection for Mac (version 2.1.1 build 110309) though from the copyright notices this looks like it hasn’t been touched since 2010… and that is the problem.
On attempting to connect to anything half way recent e.g. Server 2012, Win10, etc. you are thrown the very helpful error “Remote Desktop Connection cannot verify the identity of the computer that you want to connect to. Try reconnecting to the Windows-based computer, or contact our administrator.”
It turns out that Microsoft improved the security of RDP (always a good thing) to make use of something called Network Level Authentication [NLA]. This happened the same time Windows moved from Terminal Services to Remote Desktop Services.
What’s the difference? When connecting to a Terminal Server, a user starts a session and types in their credentials. When using an RD Session Host server, a user typically enters credentials into a client-side dialog box. NLA forces the client computer to present user credentials for authentication before the server will create a session for that user.
Because of that process, it’s sometimes called “front authentication.” Servers that are running Windows Server 2008/Vista or later, and clients running Windows XP SP3 or later, support NLA. Because NLA relies on a technology called Credential Security Support Provider [CredSSP] Protocol, if you’re using a Remote Desktop Protocol [RDP] client for another OS, you’ll need a client that supports NLA.
Microsoft Remote Desktop Connection Client for Mac doesn’t.
Fortunately there is an alternative that does. Via the AppStore, search for ‘Microsoft Remote Desktop’ – Version 8.0.36 (Build 27228) is what I have today. Install this, try and connect to your Windows machine (Win10 for me) and you are in business.
