Telnet is a character-mode terminal service which allows users to sit in front of a computer keyboard that has been online to enter the remote host through the network and then operate the remote host. This kind of connection can take place in the local area network or through the Internet. The connected computer is called Telnet Server and the machine you are using is called client or terminal. There is a component called terminal service in the win2000 system which is a graphical terminal service with more powerful functions but higher requirements on the system. Sometimes we just want to perform some simple remote management through the network so using Telnet is still a good choice.
The Telnet service in Win2000 is not started by default. We can start it in many ways. The first is the manual start method:
1. Type net start telnet at the command prompt.
2 click Start point to Programs point to Administrative Tools and then click Telnet Server Management. Type 4 at the command prompt to start the Telnet service.
3. Click Start point to Programs point to Administrative Tools click Services right-click the Telnet service and then click Start.
If you want Telnet to start automatically when win2000 starts you can also do so. Open the 'Computer Management' tool click Services find the Telnet service right-click and then click Properties. In the Startup type box click Automatic and OK.
Next let’s take a look at how to use Telnet service. The easiest way is to directly enter in command line mode:
telnet computername(or IP) Portnumber
Telnet service uses port 23 by default. If the server side If there is no modification the port number can be omitted when the client connects. If the client uses the win98 operating system you can use a special Telnet client and enter Telnet in the start menu to start it.
The above is a basic usage method. Next let’s take a look at some common problems during usage. The first one is about client login authentication. When we connect to the Telnet server on the client we often see this error message:
Server allows NTLM authentication only
Server has closed connection
This is because by default Win2000 Telnet service uses NTLM This authentication method avoids the transmission of plain text passwords and improves security. But the Telnet client client of win98 nt4.0 and other systems does not support this method which brings inconvenience. Sometimes we want to prompt us to enter the user name and password when logging in to Telnet then we can set it like this:
Start Menu|Programs|Administrative Tools|Telnet Server Management (or run tlntadmn) choose 3 to display/change the registry settings Then select 7 NTLM to modify. Acceptable values ??are 0-2 2 is NTLM only 0 is NTLM not available 1 is both supported and the default value is 2. The Telnet service needs to be restarted after modification.
In order to improve security sometimes we also modify the default port number of the service on the server side so that the client needs to provide port number information when connecting. The modification method is:
Start Menu|Programs|Administrative Tools|Telnet Server Management select 3 to display/change registry settings then select 8 Telnetport and enter the port number you want to set. Note that the port number entered should not conflict with the port being used on your server. The Telnet service also needs to be restarted after modification.
?Windows 2000 optimization