Tài liệu Adding Users in Linux pdf

1 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Lab 10.2.2: Adding Users in Linux Estimated Time: 20 minutes Objective In this lab, the student will learn how to create user accounts using the Linux Red Hat 7.X operating system. Equipment The following equipment is required for this exercise: • Computer with Linux installed • The computer will boot to the CLI not the GUI (not to X window at startup) Scenario The XYZ Company has just installed a server running Linux. The company need a IT person to log onto the server and create users. Procedures Until now, each workstation has acted independently from other computers. Each student will create user accounts and these accounts will be used in later labs. To complete the steps below, each student will need to be at the command line. If X Window was launched at boot up, then students will need to open a terminal window. 2 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Step 1: Account Planning From the drawing below, plan out how many accounts will need to be added. Assign each computer a name, which will also identify its location. User accounts may be added to the system name to identify not only the computer but also the user at that location. For example, systemA1 is used by students therefore a user account with the name: studentA1 will be used. Assign a password that is the same as the computer name in order to make the initial login easier. SystemA1 is in the first computer in row A. The computer name (host name) will be systemA1 and the student account will be studentA1 3 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. In the space below, write out a user account list. Include the computer being worked on as well. Computer Name/Location User Account/Name Password Comments Example of user accounts and host names Computer Name/Location User Account/Name Password Comments A1 studentA1 studentA1 A2 studentA2 studentA2 A3 studentA3 studentA3 A4 studentA4 studentA4 B1 instructorB1 instructorB1 Instructor, Windows Computer B2 studentB2 studentB2 B3 studentB3 studentB3 B4 studentB4 studentB4 C1 instructorC1 instructorC1 Instructor, Linux Computer C2 studentC2 studentC2 C3 studentC3 studentC3 C4 studentC4 studentC4 D1 studentD1 studentD1 D2 studentD2 studentD2 D3 studentD3 studentD3 D4 studentD4 studentD4 4 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Step 2: The useradd Command At the command prompt, type the command: man useradd What do the following switches do? -c -d -e Does the useradd command create a home directory for the user by default? If so where? ________________________________________________________________________ Step 3: The passwd Command The useradd command by itself does not automatically allow a user to login. A password must first be assigned to the user account. This is done with the passwd command. At the command prompt, type the command: man passwd Briefly describe the following passwd switches: -k -l -u -d What other means of password protection does the man passwd page discuss? ________________________________________________________________________ 5 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Step 4: Adding Users For this step, make sure to be logged in as the root user. If not already root, use the su – root command with the root’s password. With the list from step 1, create accounts for all other users in the lab. Example: Note: Part of the password for these accounts can be found in a dictionary (the word “student”). Linux will warn against using these passwords for security reasons, but it will accept them. All passwords must be entered twice. Notice that in the example above, this is a two-step process. First, create the account with the useradd command and then give the new user account a password with the passwd command. 1. Type: useradd studentXX (where XX is the username from the table in step 1), and then press Enter. 2. Type: passwd studentXX Use the student account for the password. Linux will ask the user to enter the password twice to check for accuracy. 3. Continue this procedure until all the users are added to the systems. 6 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Step 5: Account Verification In this step, verify that the accounts were created correctly in step 4 by using the finger command. To learn about the finger command type: man finger Experiment with the finger command, type: finger root Briefly describe the output of this command? Verify that the accounts were created correctly in step 4. Randomly pick six accounts and use the finger command to see if they were created correctly, List the results in the table below. Account name Verified Y/N Step 6: Deleting Users To delete an account, the Linux administrator uses the userdel command. Read the man page on the userdel command, type: man userdel Describe the –r switch when it is run with the userdel command. To test the userdel command create a temporary account, type: useradd temp123 Note: This account does not need a password since this is only a temporary account. To see if the account was created, type: finger temp123 Was a home directory created? Y/N Next delete the temp account, type: userdel –r temp123 7 - 7 IT Essentials II v2.0 - Lab 10.2.2 Copyright  2002, Cisco Systems, Inc. Does the account still exist? Type: finger temp123 What was the output of this command? ________________________________________________________________________ Troubleshooting To create accounts in Linux, the user must be logged onto the server as an Administrator. If problems are encountered while creating these accounts, verify that the user has the necessary administrative privileges by logging off of the server and logging on again using the Administrator account. Reflection Why is it important that only an administrator is allowed to create user accounts? ________________________________________________________________________ . Inc. Lab 10.2.2: Adding Users in Linux Estimated Time: 20 minutes Objective In this lab, the student will learn how to create user accounts using the Linux. users in the lab. Example: Note: Part of the password for these accounts can be found in a dictionary (the word “student”). Linux will warn against using