What do I do if I cannot connect to a Windows ECS instance by using the default port 3389? -

This topic describes the cause of and solution to the issue that you cannot connect to a Windows Elastic Compute Service (ECS) instance by using the default port 3389.

Problem description

You cannot use Remote Desktop or Workbench to connect to a Windows ECS instance on the default port 3389.

Cause

The preceding issue may occur if the Remote Desktop Services port is changed from the default port 3389 to another port on the Windows ECS instance.

Note

To ensure security in specific scenarios, you must change the Remote Desktop Services port to reduce the number of malicious RDP attacks and RDP scans on the ECS instance.

Solution

Connect to the Windows ECS instance by using Virtual Network Computing (VNC).
For more information, see Connect to an instance by using VNC.
Choose and enter regedit to open the Registry Editor window.
In the address bar, enter the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp path and press the Enter key. Then, find the PortNumber value.
The following figure shows that the PortNumber value is 3388, which indicates that the Remote Desktop Services port on the ECS instance is port 3388.
- If the port is the expected port, specify the port when you connect to the ECS instance.
- If the port is not the expected port, proceed to Step 4.
Change the Remote Desktop Services port.
1. Right-click the PortNumber parameter and select Modify...
2. In the dialog box that appears, set the Base parameter to Decimal and the Value data parameter to the port number that you want to use, such as 3389.
3. Click OK.
Restart the Windows ECS instance to allow the change to take effect.
For more information, see Restart an instance.
Reconnect to the Windows ECS instance.
Set the logon port to the port that you specified in Step 4. If you can connect to the instance, the preceding issue is resolved.