Troubleshooting RDP Client Connection Problems

MORE INFORMATION

The Terminal Server Client connects to the Terminal Server through a TCP socket connection over port 3389. The basic requirements for a connection are the following:

• The Client needs a functional connection to the network using TCP/IP.
• The Server connection needs to be functional.
• The user needs permissions to connect.

If a Client cannot connect:

1. Does the client computer have Microsoft TCP/IP installed? If not, install the TCP/IP protocol.
2. If the client computer uses Windows For Workgroups 3.11, is TCP/IP-32b installed? This version of TCP/IP is required for WFW and is located on the Windows NT 3.51 or 4.0 Server CD-ROM as well as the Terminal Server 4.0 CD-ROM in the Clients folder. Install the Windows for Workgroups Update files in this same folder also.
3. Does the client computer have normal network connectivity over TCP/IP to the Terminal Server? If other protocols are installed on the client, you may want to remove them for testing purposes.
   • Can you ping the Server?
   • Can you telnet to port 3389 from the Client to the Server?
   • Can you use the command "Net View \\computername" against the Terminal Server and get a list of shared resources available?
     
     NOTE: While NetBIOS connectivity is not necessary for the Terminal Server Client, this can help you determine the state of your network connectivity.
     
     
   • Can you connect to and use Terminal Server shared folders from the client computer?
     
     NOTE: This is not necessary for Client functionality, but can help determine if your network is healthy.

If these tests fail, you have a network connectivity problem, not a Terminal Server Client problem. If you can do everything except telnet to port 3389, perhaps you have a firewall blocking the port. This port is required for the Terminal Server Client. Since the client protocol (RDP) is encapsulated within TCP/IP, you can troubleshoot a network connectivity problem with the client exactly as you would any TCP/IP connectivity issue.

• Log on at the Terminal Server console as an administrator and install the Terminal Server Client on the Terminal Server. Start the Client directly on the Terminal Server console and try to connect to the same connection that the failing client is trying to reach. Does this work at the console?
  If so, then the connection is functioning.
• Log on at the Terminal Server console as the user who is trying to use the client. Can you run the Terminal Server Client as this user at the console?
  If so, the connection is functional and the user has appropriate permissions to use the connection.

If the previous tests fail, check the following:

• In Terminal Server Connection Configuration, highlight the connection and check Security/Permissions on the menu. Does the user have at least guest access to the connection?
• In Terminal Server Connection Configuration, view the properties for the connection. Has the Maximum Connection Count been set? Check the Unlimited box for testing purposes.
• In Terminal Server Connection Configuration, view the properties for the connection and open the Advanced properties screen. Is the connection enabled? If this is disabled, no one is able to connect.
• In Terminal Server License Manager check to see that you have available client licenses. This tool is for Client licenses.
• In License Manager check to see that you have available Client Access Licenses. This tool is for Server access licenses.NOTE: Clients require both a Client (NT Workstation) license and a Client Access License (Server access). These licenses are purchased separately.
  
  
• If the user cannot log on at the Terminal Server console, the client is also unable to connect. The error message you receive is that the user is not allowed to log on interactively. The user must have the right to log on locally at the console. This is set in User Manager under Account Policies/Log on Locally. If the Terminal Server is a domain controller, policies are set at the PDC and are valid for all domain controllers in the domain.
• If the user cannot logon at the Terminal Server console but has the right to do so in User Manager Account Policies, check the user's account. The ability to log on locally can be disabled on a per user basis in the Config screen for the user. Make sure "Allow logon to Terminal Server" is checked.