Windows Server 2008 R2 RDP doesn't work

Dear Expert,

I had serveral phone calls about not working RDP to Server 2008 R2 since this morning.
For example server SRV-TEST. I can ping to and from SRV-TEST. I cannot use RDP to connect to the server. I did not install updates yesterday.

- restart of SRV-TEST did not help
- restart of router did not help-
- I can use RDP from SRV-TEST
- I cannot TDP to SRV-TEST internally nor externally (NAT)
- ping works fine both directions, I can browse file shares on

Do you have some tip?

Jaroslav LatalMSPAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

First step - Check if the server is listening on port 3389.  Use Netstat -nat to verify that tehre is a Local Address of as shown in the following screenshot:

If this does appear, then check the firewall rules to ensure that you have allowed Remote Desktop

If this is also good, then check your network adapters on the server to ensure that it hasn't accidentally slipped into "Public", and that it is either Domain or Private.

Of course, you need to have physical access to your server to check all of the above.  If this is a virtual server, then use the relavant virtual machine console to view the server - since RDP does not work.  If you are unable to connect to the server (physically not possible), then reboot the server using the following command line:

shutdown -r -t 1 -m

Let us know how you get on.

P.S. I know my screenshots are done from Windows 2012 R2 but the information is still valid for Windows 2008/2008 R2
Jaroslav LatalMSPAuthor Commented:
Hi Lester,

netstat -net shows "lsitening", same as on your printscreen.
I double checked firewall, it is also OK. (finally I turned firewall off)
Server is not in public network.

I found strange behavior. When I try to connect million times, it works for one of million connection). When I disconect the session, I'm unable to connect again. Maybe another million attempts will help...

Very odd behaviour... Not sure what to suggest anymore :)
Jaroslav LatalMSPAuthor Commented:

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Jaroslav LatalMSPAuthor Commented:
It was some kind of DOS.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Windows Server 2008

From novice to tech pro — start learning today.