Terminal Emulation (TELNET)

Terminal Emulation (TELNET)

TELNET protocol is used to match such as terminals connected to a remote host (remote). The principle works using TCP as transport protocol for sending information from the user's keyboard into a remote-host and display information from remote-host to the workstation to the user.

Telnet Server tools and settings determine how Telnet Server handles auditing, authentication, idle session time-out, and other remote command console session options. Usually, you do not need to configure Telnet Server options to connect a Telnet client to Windows Server 2003-based Telnet Server: the default Telnet Server options are compatible with most Telnet clients. However, you must configure Telnet Server options if you want to do any of the following:
Audit logon and logoff information.

Disable NTLM or password authentication, or change the default domain for authenticating unqualified user names (by default, the domain in which the machine account resides is used to authenticate unqualified user names).

Prohibit authentication of user accounts in trusted domains, which restricts Telnet access to users whose user accounts are stored only in the local Security Accounts Manager (SAM) database (by default, Telnet Server authenticates user accounts in trusted domains and the local SAM database).

Change the default shell, or command interpreter, that is used for Telnet sessions (Cmd.exe is the default shell).

Specify an IP address on which you want the Telnet Server program to listen for connection requests.

Change the mode of operation from console mode to stream mode.

Ensure that all programs started in a Telnet session terminate when you disconnect a Telnet session.

Change the TCP port on which Telnet Server listens for a connection (by default, Telnet servers listen on TCP port 23).

Change the maximum number of Telnet sessions that Telnet Server will accept (the default is 2).

Change the maximum number of logon attempts before a user is disconnected (the default is 3).

Disable idle session time-out, or change the idle session time-out value (the default is 1 hour).

Disable Alt key mapping (by default, pressing Ctrl-A simulates the Alt key).

Telnet Tools

The following tools are associated with Telnet Server.
Telnet.exe: Telnet Command Prompt
Category

The Telnet command prompt tool is included with the Windows Server 2003 and Windows XP operating systems.
Version compatibility

Use this command on computers running Windows Server 2003 or Windows XP.

Once all of the settings and options are configured, you can use Telnet.exe to initiate and conduct a Telnet session. You can create a Telnet connection, configure Telnet.exe options, and use all Telnet.exe features by using the Telnet command prompt. The Telnet command prompt is useful if you are performing quick maintenance tasks on several different hosts or you need to use advanced Telnet options and features.

You can access the Telnet command prompt by running the Telnet command without any command-line parameters. You can also access the Telnet command prompt by typing the Telnet escape character during an active Telnet session. The default escape character is Ctrl+].

After you start the Telnet command prompt, the following message appears:
Welcome to Microsoft Telnet Client
Escape Character is 'Ctrl+]'
Microsoft Telnet >

You can close the Telnet command prompt by using the Quit command.
Telnet.exe with command-line parameters

You can create a Telnet connection and configure some Telnet.exe options by using the Telnet command in conjunction with various command-line parameters. Using the Telnet command with command-line parameters is helpful if you are creating Telnet connections within a script or batch file or you do not need to use advanced Telnet client options and features. When you use Telnet with command-line parameters, you can use a single command to create a connection with a host. The command-line syntax for Telnet.exe is:

telnet [-a][-eescape_char][-flog_file][-luser_name][-tterm]host [port]