Telnet Developments

In the October 28, 1999, Windows 2000 Pro UPDATE newsletter, I asked whether I'm the only Windows 2000 (Win2K) or Windows NT user who still uses Telnet. The question came up after I discovered major changes in the Win2K Telnet implementation between Release Candidate 1 (RC1) and RC2. The response from readers was overwhelming—they're definitely still using Telnet. For those readers who aren't familiar with Telnet, it's a way to extend a command prompt over the network. You run a Telnet server on a host machine and a Telnet client on another machine on the network. On the client, you can then access a command prompt or a special-purpose application from the Telnet server.

Win2K RC1 and NT provide a simple Windows-based Telnet application. One benefit of this program is that it lets you easily capture text to a log file: Select Start Logging from the Terminal menu, do what you need to do online, select Stop Logging, and save the resulting text file. The Win2K RC1 and NT Telnet client features a familiar Windows look that includes options and settings on various menus, as Screen 1, page 220, shows. This interface simplifies using the application and helps new users who are accustomed to Windows discover the application's features. However, the Win2K RC1 and NT Telnet application is far from the best product on the market. The program is slow and primitive, and it provides for only two hardware terminal emulations.

The Telnet application that Windows 2000 Professional (Win2K Pro) RC2 includes isn't a Windows application—it's a character-mode application that runs in a Win2K Pro command prompt, as Screen 2, page 220, shows. The new Telnet application lacks a menu bar and provides a unique two-level text-menu user interface (UI). If you run the Telnet application without specifying a connection or port, the system will present you with the following information:

Microsoft (R) Windows 2000 (TM) Version 5.00 (Build 2128)
Welcome to Microsoft Telnet Client
Telnet Client Build 5.00.99201.1
Escape Character is 'CTRL+\]'

Microsoft Telnet>

For a list of commands, type


and the system provides a list of abbreviated commands. Table 1, page 220, lists the action that each command performs. To return to the command list from an active session, press Ctrl+\].

If you want to access a nonstandard port, the new application accepts a port number in the command prompt. By default, the application uses port 23, which is the default Telnet port. However, on most Web servers you can telnet to port 80 to view the raw HTML that the Web server delivers.

When you run Telnet from the command line and type


at the prompt, the system outputs the following information:

Microsoft Telnet> display
Escape Character is 'CTRL+\]'
WONT AUTH (NTLM Authentication)
Sending both CR & LF

Preferred Term Type is ANSI
Microsoft Telnet>

This information shows that the new Telnet application, by default, disables the NT LAN Manager (NTLM) Authentication option and sets the Preferred TermType option to ANSI, as the old Telnet application does. However, Win2K Pro RC2's Telnet application lets you use the Set command to change these default settings. To enable NTLM authentication, type

set ntlm

NTLM authentication is the most significant feature that Microsoft added to the new Telnet application. When you use NTLM authentication with a compatible Telnet server (e.g., a system running Windows NT Services for UNIX—SFU), NTLM authentication provides a secure logon method. If you don't enable this function, the server transmits usernames and passwords in clear text, and anyone with a network sniffer can read them.

To enable the Telnet application's other new feature—a new emulation that supports complex console-mode applications (e.g., edit.exe)—type

set term vtnt

This feature works only if you're connected to a compatible Telnet server (e.g., a system running SFU).

Windows NT Services for UNIX
SFU is a Win2K and NT 4.0 add-on kit for mixed environments that include UNIX systems. (For an overview of SFU, see "Microsoft Windows NT Services for UNIX," page 135.) This kit contains a more sophisticated version of the new character-mode Telnet client, a compatible Telnet server that supports authenticated logon and the new VTNT emulation, an NFS client and server, a Network Information Service (NIS) server, a password-synchronization daemon, and a UNIX-style command-line shell and utilities.

The Telnet application SFU includes has one major feature that Win2K RC2's Telnet application lacks—logging. Use the Set Logfile and Set Logging command to enable logging. Microsoft plans to add this updated version of Telnet to Win2K Pro, probably in Service Pack 1 (SP1).

However, you don't have to wait for logging functionality. To get logging functionality with Win2K Pro's RC2 Telnet application, right-click the command prompt icon in the title bar of a command prompt window, select Properties, and select the Layout tab. Increase the Screen Buffer Size Height option to 999 lines, and click OK. The system asks whether you want to apply the new properties to only the current window or to the shortcut that opens the window. If you plan to perform this action often, select the shortcut option.

After you set this option, launch Telnet from the command line. The current command prompt opens with a 999-line buffer. After you perform the actions you want to log, simply right-click the command prompt window's title bar, and select Edit, Select All and Edit, Copy. Paste the results into a Notebook file, and you've created a log. This method is complicated, but it works.

If you prefer the old Telnet application to Win2K Pro RC2's Telnet application, you can keep the old application after you upgrade. Copy telnet.exe from your NT 4.0 CD-ROM. However, if you put telnet.exe in your \windows\system32 directory, rename the file. Otherwise, Win2K's new system-file-protection feature will replace the old application with the new version.

If you don't want to bother with Microsoft's Telnet application, alternatives are available. For example, Hilgraeve's HyperTerminal ships with Win2K Pro and provides Telnet support, a superior range of terminal emulations, and logging functionality. To run this program on your Win2K system, select Programs from the Start menu, and select Accessories, Communications. Many other commercial alternatives exist, and you can find freeware and shareware Telnet applications on the Web.

TAGS: Windows 8
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