Hello, I manage a network of a lot of clients and servers, with mixed operating systems, and in some of them I have a serious problem to establish a quick connection via rdp to my servers.
The problem is that when I start the connection, I have to wait about 30seconds (some times also more) before to receive a reply from the server and to start the session.
The strange is that if I execute a ping command to the same server when I start the connection to, I have to wait about the same time before to receive the firt reply, like is the problem could be network related, and not protocol related.
When the communication become "unblocked", and I start to receive packets, I'm also able to connect via rdp. This situation is completely reproducible, because I can reproduce the same behavior on the same clients in every moment.
Every time I notice that when the communication become "unblocked", then all become quick, and I can ping the server receiving an immediately response as to connect via RDP.
The clients have this problem with every server in the network, so it seems to be server-OS independent (the server involved are running Windows server 2003 R2, Windows server 2008 and 2008 R2).
On the other side the problem seems to be clients dependent, because until now I was unable to reproduce the problem using Windows XP, while I'm sure to have randomly with Windows Vista, Windows 7 and Windows 8.
I googled and technetted for a long time before to ask here, trying every plausible solution in order to solve the problem.
Some solution I remember to have applied are:
-enable the enablecredsspsupport command setting it to 0 like explained in this thread: http://social.technet.microsoft.com/Forums/windowsserver/en-US/b8e58d83-3178-4490-b4f4-1c6e5542c39a/rdp-slow-initial-connection
-setting the RDP compression algorithm like explained here: http://social.technet.microsoft.com/Forums/windowsserver/en-US/5fa75908-663a-47ec-9038-dc44afb0d2bc/rdp-connections-suddenly-slow
-I also tried to set up some other criteria about certificates (see images attached) but none of them have solved my problem.
I'm having this problem from some months and its affecting some dozens of clients, so I need help to investigate more deeply to solve the problem. I exclude that it could be a network related problem because the clients that have the problems are randomly in different networks positions (the network cover a large area with more business units located in different towns), while in different hosts in the same network segment (two neighbour patches) some could present the problem and some other no.