Tài liệu Configuring Telnet on Windows 2000 pdf

Lab 8.5.3: Configuring Telnet on Windows 2000 IP IP Linux Server Workstation or another server Estimated Time: 40 Minutes Objective In this lab, the student will learn how to configure

Lab 8.5.3: Configuring Telnet on Windows 2000

IP

IP Linux Server

Workstation (or another server)

Estimated Time: 40 Minutes

Objective

In this lab, the student will learn how to configure Telnet services on Windows 2000

Equipment

The following equipment is required for this exercise:

• A system running Windows 2000 Professional

• Network connection from the workstation to hub or switch

• PC with a Telnet client program connected to the same hub or switch

Scenario

The ABC Company has just installed a server running Windows 2000 The company has asked that Telnet services be configured so that the workstation can be remotely

administered using Telnet

Procedures

Before beginning this lab, make sure that both the Windows 2000 workstation and the

for both hosts Record that information in the tables provided:

Connected Host IP Address Configuration

IP address:

Subnet mask:

Default gateway:

Local Host IP Address Configuration

IP address:

Subnet mask:

Default gateway:

Record the IP address of the server and workstation in the boxes provided in the network diagram

Step 1: Log in to Windows 2000

Once the Windows server boots, the “Welcome to Windows” dialog box appears Log in

as the administrator

Step 2: Setting the IP address

Configure the Windows 2000 workstation IP address, subnet mask, and default gateway

to match the information entered in the table If this information has already been

configured in a previous lab, get the other workstation’s information Configure the

workstation IP stack accordingly Use ping to verify that the server can communicate

Step 3: Open Administrative Tools

On the workstation, start the Computer Management console Go to Start > Programs >

Administrative Tools

Step 4: Services and Applications

Once the Computer Management window displays on screen, click the plus (+) symbol to the left of “Services and Applications” and select Services from the expanded tree

The Services section contains controls for starting and stopping the various services that are run in Windows 2000

Step 5: Configuring the Telnet Service

In order to allow Telnet clients to connect to the workstation, the Telnet service must be started Scroll the right-hand pane until the “Telnet” service is visible

Notice that the “Status” column is blank for the Telnet service indicating that the service is not currently running To start the Telnet service, right-click on the service and select

Start from the menu

A Status indicator displays as Windows attempts to start the service Check the Status

column and verify that the service has started

Step 6: Locating the Telnet Service

The Telnet service for Windows 2000 defaults to using NT LAN Manager NTLM

authentication, which is not supported on all systems In order to make sure that the

Telnet service will work with any Telnet client, the service needs to be configured to

accept clear text usernames and passwords, if NTLM authentication fails To do this, start Telnet Server Administration, which is located in the Administrative tools menu next to

Computer Management

Step 7: Telnet Administration

The Telnet Server Administration program is a menu driven program, to allow plain text

as well as NTLM Press 3 to enter the “Display / Change the registry settings” section of

the program At the next menu, choose 7 for NTLM The default value for NTLM is 2,

which does not allow clear text authentication in any circumstances Changing the NTLM

value to 1 will allow clear text authentication if NTLM fails The following dialog with the

menu will change NTLM to 1:

Current value of NTLM = 2

Do you want to change this value? [Y/n] y

NTLM [current value = 2; acceptable values 0, 1 or 2]: 1

Are you sure you want to set NTLM to: 1? [Y/n] y

Activate the changes that were just made by Stopping and Restarting the Telnet service

Note: Although it is convenient to allow clear text authentication so that clients can have

unrestricted access to the Telnet service (provided a valid user name and password are

present during the Telnet login), it is not recommended that clear text authentication be

enabled on a production server

Step 8: Starting the Telnet Session

To restart the Telnet service, enter a 0 to return to the main menu, and press the

The Telnet service could be initially started from here as well as the Computer

Management console Now that the Telnet service has been started and configured on

the Windows 2000 workstation that will be used to Telnet into, the other workstation

should be able to test the connection to it using a Telnet client

Add netstat –a command to verify connections

Step 9: Run Command Window

Go to another workstation and test this connection On the workstation, the easiest way

to start a Telnet session to the Windows 2000 server is to go to Start > Run and enter

telnet ip_address_or_hostname

Once the Telnet client window comes up, it may warn that the user is about to send

password information through the Internet zone and it will prompt for permission Click

Yes and the window will display as shown below

A Telnet session is comparable to having a command prompt open on the Windows 2000

server From here, the system can be manipulated remotely

Step 10: Remote System Statistics

In some environments, the statistics of the computer being logged into may not always be known There are some commands and programs that can give useful information about the server being logged in to Among these is the ver command, which displays the

version of windows that the system is running Type ver into the Telnet window and

press Enter Output should appear similar to the output displayed below

C:\>ver

Microsoft Windows 2000 [Version 5.00.2195]

C:\>

The netstat -a command is also very useful in tracking connections to the server

While logged in to the server, a user can run programs and issue commands, provided those commands do not require the GUI

When finished with the Telnet session, type exit at the command prompt Exit will end the Telnet session

Troubleshooting

This lab requires that the two workstations have TCP/IP connectivity with each other If the user cannot telnet to the server from the workstation, verify each system’s IP

configuration and physical connections to the network

If the Telnet session is opened, but the user cannot log in, verify that the username and password being used have been configured on the server

Also, verify that NTLM authentication has been disabled, as described in Step 6 of this lab

Reflection

1 Telnet allows administrator remote access to the server What kind of administrative tasks can be performed using the Windows CLI through Telnet?

2 Telnet service is not enabled by default on a Windows 2000 server What are the dangers of enabling Telnet services?