rdsterminalwindows-server-2012-r2
I've just setup a new RDS Deployment on a 2012 R2 domain. When client's connect to the RemoteDesktop there is a considerable delay at the "Preparing the destination computer" stage. I can resolve this by disabling the Windows Firewall on the RDS Session host computer.
I've searched the web and checked all open ports and it appears I've added the required exceptions for everything, but this is still happening whenever I turn the Firewall Back on.
This references Windows 8/8.1, but applies to 2012/R2. Be sure to read to the bottom as there are some great QAs for things like you're experiencing where not everything shows up. I've included a screenshot for reference, but basically when users don't see all the tiles/apps it's USUALLY because of three major things:
A) You didn't apply the layout to the default profile
B) You didn't install/configure a custom app, or third party app, correctly on the computer in question, and the computer doesn't recognize it as being installed locally.
C) Permissions used to export/import the XML/start layout.
This is by design, RDWeb and full RDP session are using different services.
Best Answer
Check the Security log when the Firewall is on and see if you can find any blocked entries from the IP that's connecting.
Also, check the number of rules in the Firewall and consider disabling/deleting some extraneous ones if there are a lot; if there are too many rules it can actually slow down the response time because it has to process every rule.