I can access the machine via RDP from another client, from exactly the same network, through exactly the same forwarded port.
What might be causing remote desktop client to hang today? It usually works.
The TCP connection is made, and I'm prompted for credentials. Then, hang ...
Alas, very soon after posting the question, I found what seems to be the root cause. The RDP client seems to be oblivious to a server side socket close, due to bad credentials. When I put in the correct password, it succeeds!
I hope other people benefit from this Q&A. A case of what looks like a connection problem is actually stupidity in the RDP client.
Here are the last two packets from a tcpdump trace:
09:29:05.977126 IP server.3389 > client.65355: F 1292:1292(0) ack 1438 win 7965
09:29:05.978195 IP client.65355 > server.3389: . ack 1293 win 16229
The server (actually a port forwarding server, not the Windows machine) has send a FIN packet, indicated by the F. The client TCP stack acks it, but the application remains oblivious to the one-way close and keeps displaying the connection attempt dialog box.
I have reproduced it several times. When I disconnect and try to reconnect with the wrong password, it hangs. Right password, and it proceeds. Maybe in another ten years they will get RDP right.
P.S. the other client not displaying the behavior is a free app for Android.
I faced similar issue today. I was first time trying to access machine using tunneling through putty.
It turned out to be issue with completeness of credentials. I missed domain name before user name which we normally don't add while connecting.
Different circumstances, similar result.
Only my workstation (Windows 10 64-bit) was affected. I cloned a Citrix VM in our farm running Windows 7 64-bit so our developer could have a little sandbox for testing. After I got the AD registration sorted for both VMs (the original and the copy), RDP would not work from my machine using any credentials, local or domain. Could not even use the IP address to connect. In all cases, the connection dialog box would freeze after I entered credentials.
The discussion in this thread led me to review the credential manager to see if there were entries I could clear. When I saw it was blank, I took a shot and CREATED entries. That fixed it. No idea why, but there it is.
If you are on a LAN that does not have internet access, you'll have to disable the computers from trying to phone home and get certificate updates (this causes a delay when initializing RDP sessions)
Guide: http://www.batchworks.de/remote-desktop-client-hanging-at-securing-remote-connection/
The way I finally solve this problem is uninstall the Remote Desktop Connection Broker. It waste my whole day to eventually figure out it. There must some setting to configure this hanging in Broker, but I don't have enough time to dig in, so I just simple uninstalled it. Hope someone can find the way to change it~
Often I have seen issues with credential corruption and this was the case in my case. Find the credential in credential manager for the RDP connection and delete it. It is an app in control panel. Had similar issues while as a support person at Microsoft and it just came to me to try it and it worked for me. Nothing else worked, reboot, trying to reenter password, etc. I think adding the FQDN as Sachin pointed out could possibly get you a new credential, which would allow it to work. If if works in other apps/computers, then windows credential stored for the connection is possibly corrupt, delete and connect again and it will work. Happens very rarely...twice in 20 years for myself that I know of.
