Telnet which we talked more about in “Enable Telnet In Windows 10 and Server 2012 R2” post. In this article we trying to talk about troubleshooting telnet errors in Windows environment. It is not difficult to troubleshoot telnet errors messages, but in some cases, it is a bit hard to get the exact problems. What and why it happened. So we trying to explain the cause of errors message and going to show you, how to solve them.

I’m testing these problems on Windows Server 2021 and Windows 10 and it must work the same on all Windows environments. Most of these solution work for Linux, Mac OS and other network devices which integrated with the telnet protocol.

Troubleshoot Telnet Errors Messages On Windows Environment

As my experience with troubleshooting network and system errors. I should tell you, when you face errors, read the message completely and try to get the cause of issues. So when you clearly understand the message you will simply find a solution for. Otherwise, you will fail even with a simple error.

1. System Error 1058: Telnet Service Fails to Start  Or Connecting to 192.168.100.2 … Could not open a connection to the host, on port 23: connect failed.

It occurs when the telnet service is stop or disabled. To solve this problem, go to services and enable telnet service. If you don’t know to enable, read the “Enable Telnet In Windows 10 and Server 2012 R2” post.

 2.  Access Denied – The specified user is not a member of the TelnetClients group

The message tells us, the user and password you enter it is not member’s of TelnetClinets group. You see the solution is within this message. “Server administrator must add this user to the above group”.

To solve this error, just add the user to the TelnetClients group. For security, the reason doesn’t add everyone group to Telnet Clients group.

3. Error while connecting to the host – could not open a connection to host on port 23

You might see the Connecting to 192.168.100.2 … Could not open a connection to the host, on port 23: connect failed errors. It’s also from the blocked port by firewall or Antivirus software.

To solve this error, enable the telnet from firewall settings or create and a rule from Windows firewall inbound rules.

Sometimes the port 23 is not set as the default port for telnet. You can set and changed it with the following tlntadmn command.

tlntadmn \\ms2 config port=23

In the command, ms2 is the computer name which I want to change the telnet port number to 23.  If it does not work, once reset the firewall settings from the Windows firewall and Restore default.

4. You Cannot Access Drive Letters Mapped by Others in Separate Telnet Sessions

This error happened rarely when multiple users are logged on to a Telnet server. One user maps one or more network resources to drive letters, and another user expects those drive letters to be available to all users on the Telnet server.

To solve this error, each user must employ the net use command or net user command to map network drives to drive letters individually, according to their own needs.

 5. The user has not been granted the requested logon type at this computer

I never see this error yet, so can’t tell you the exact solution. So read the Microsoft solution at Technet website. https://technet.microsoft.com/en-us/library/cc732593(v=ws.10).aspx

Related article: How to Configure SSH on Linux?

Your homework!   Solve this one for me. Error Message: No more connections are allowed to the telnet server. Please try again later. —  Connection to host lost.

Finally, telnet errors are more than these 5 common telnet issues. If you know any complicated errors, so share and add yours to the list in order to complete troubleshoot telnet errors message and solutions.

The post How to Troubleshoot Telnet Errors in Windows OS appeared first on TECHNIG.

Controlling Windows Servers remotely is a daily activity of a network and system administrators, whether with command line or remote desktop. Here I’m using Telnet command Line tool. Telnet is a protocol that enables you to connect remotely to computers. By default the telnet services is not enabled on Windows Server and Clients. I’m going to show you how to enable telnet in Windows 10 and Windows Server 2012 R2 or vNext Server. So you need to know the telnet port also. The default port of telnet is 23 and when you enable telnet on Windows, you make sure that the port 23 is not blocked by Windows Firewall or Anti Virus. 

Telnet is not a good chose to control a system over the internet. Because it is not secure and the communication is occurred on a non encrypted mode. If you want to secure Telnet communications, you must do it with Internet security protocol (IPSec). Securing telnet is out of scope of this topic, we simply enable telnet in Windows 10 client and Windows Servers. It work the same on Windows Server 2008, Windows 7, 8 and Windows 8.1.

Enable Telnet In Windows 10 Client Side

Firstly, we must enable telnet in Windows 10 and next on Windows Server. To work perfectly, telnet client must installed on client side and telnet Server must be installed on Server side. In order to enable telnet, go to control panel -> Programs and Features -> and click Turn Windows Features on or off.

For an expert it is a very long way, so just type “optionalfeatures” on the Run and press enter to open Windows Features page.

On the Windows Features page, tick the Telnet Client and click on to install it. It take a minute and when the installation complete successfully, close the page. That is it, Telnet installed successfully on Windows 10.

Enable Telnet on Windows Server 2012 R2

OK the next step is enabling telnet on Windows Server. No matter which server you are using. In Server side it is not enabled like Windows client, you must enabled trough Server Manager. Becuase it is Feature base and all are controlling with Server Manager console.

On the Server Manager‘s of Windows Server, click Manage and then click Add Roles and Features.

On the Installation Type page select Role-based or feature-base installation and click Next.

Select the Server you want to install telnet on the destination Server page. In this test environment, we have only one server and by default it has been selected. Don? So click Next.

On the Server Role page, do nothing and just click Next. So we want to install features not Roles. And I don’t take Screenshot, it is going to make heavy my article.

So on the Windows Feature tick both Telnet Server and Telnet Client then click Next to install it and go to Confirmation page.  On the Confirmation page click Next and it takes a few minutes, so be patient.

Finally, when the installation finished successfully, click Close and go to enable Telnet service from Services. To open Services on Windows Server, search for Services to find it.

On the Services page find Telnet and click twice to open telnet properties. Now select Automatic and click Start button then click OK and close the services console.

 Test Telnet Services on Windows

Try to test the telnet whether it work or not. In order to test telnet, go to Windows 10 and open command prompt or PowerShell. and type the following command.

Telnet 192.168.100.2

It is the IP Address of Server that I want to control it with Telnet.

So when you press enter, the system ask you about sending password to a remote computer trough internet.

This is about sending your user name and password trough a non secure internet line which I told you about securing telnet with IPsec. So type “Y” and press enter.

Type user name and password correctly and press enter.

Welcome to the telnet session from Windows 10 to Windows Server 2012 R2 that work perfectly. Now the Server 2012 R2 is completely under your control. Test and run some command for test.

The post How to Enable Telnet In Windows 10 and Server 2012 R2? appeared first on TECHNIG.