CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 151:

  A Linux administrator is troubleshooting an issue in which users are not able to access https://portal.comptia.org from a specific workstation. The administrator runs a few commands and receives the following output:

  

  Which of the following tasks should the administrator perform to resolve this issue?

  A. Update the name server in resolv. conf to use an external DNS server.

  B. Remove the entry for portal . comptia.org from the local hosts file.

  C. Add a network route from the 10.10.10.0/24 to the 192.168.0.0/16.

  D. Clear the local DNS cache on the workstation and rerun the host command.

  Correct Answer: B

  The best task to perform to resolve this issue is B. Remove the entry for portal.comptia.org from the local hosts file. This is because the local hosts file has a wrong entry that maps portal.comptia.org to 10.10.10.55, which is different from the

  actual IP address of 192.168.1.55 that is returned by the DNS server. This causes a mismatch and prevents the workstation from accessing the website. By removing or correcting the entry in the hosts file, the workstation will use the DNS

  server to resolve the domain name and access the website successfully.

  To remove or edit the entry in the hosts file, you need to have root privileges and use a text editor such as vi or nano. For example, you can run the command:

  sudo vi /etc/hosts

  and delete or modify the line that says:

  10.10.10.55 portal.comptia.org Then save and exit the file.

• Question 152:

  A developer wants to ensure that all files and folders created inside a shared folder named /GroupOODEV inherit the group name of the parent folder. Which of the following commands will help achieve this goal?

  A. chmod g+X / GroupOODEV/

  B. chmod g+W / GroupOODEV/

  C. chmod g+r / GroupOODEV/

  D. chmod g+s / GroupOODEV/

  Correct Answer: D

  The chmod command is used to change the permissions of files and directories on Linux systems. The g+s option sets the setgid bit on a directory, which means that all files and folders created inside that directory will inherit the group name of the parent directory. This command can help the developer ensure that all files and folders created inside the /GroupOODEV directory have the same group name as /GroupOODEV. References: [How to Use chmod Command in Linux with Examples]

• Question 153:

  Which of the following files holds the system configuration for journal when running systemd?

  A. /etc/systemd/journald.conf

  B. /etc/systemd/systemd-journalctl.conf

  C. /usr/lib/systemd/journalctl.conf

  D. /etc/systemd/systemd-journald.conf

  Correct Answer: A

  Explanation: The file that holds the system configuration for journal when running systemd is /etc/systemd/journald.conf. This file contains various settings that control the behavior of the journald daemon, which is responsible for collecting and storing log messages from various sources. The journald.conf file can be edited to change the default values of these settings, such as the storage location, size limits, compression, and forwarding options of the journal files. The file also supports a drop-in directory /etc/systemd/journald.conf.d/ where additional configuration files can be placed to override or extend the main file. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Automating Tasks; journald.conf(5) - Linux manual page

• Question 154:

  Users have reported that the interactive sessions were lost on a Linux server. A Linux administrator verifies the server was switched to rescue.target mode for maintenance. Which of the following commands will restore the server to its usual target?

  A. telinit 0

  B. systemct1 reboot

  C. systemct1 get-default

  D. systemct1 emergency

  Correct Answer: B

  Explanation: The systemct1 reboot command will restore the server to its usual target by rebooting it. This will cause the server to load the default target specified in /etc/systemd/system.conf or /etc/systemd/system/default.target files. The telinit 0 command would shut down the server, not restore it to its usual target. The systemct1 get-default command would display the default target, not change it. The systemct1 emergency command would switch the server to emergency.target mode, which is even more restrictive than rescue.target mode. References: [CompTIA Linux+ (XK0-005) Certification Study Guide], Chapter 17: System Maintenance and Operation, page 516.

• Question 155:

  A junior systems administrator has just generated public and private authentication keys for passwordless login. Which of the following files will be moved to the remote servers?

  A. id_dsa.pem

  B. id_rsa

  C. id_ecdsa

  D. id_rsa.pub

  Correct Answer: D

  Explanation: The file id_rsa.pub will be moved to the remote servers for passwordless login. The id_rsa.pub file is the public authentication key that is generated by the ssh- keygen command. The public key can be copied to the remote

  servers by using the ssh- copy-id command or manually. The remote servers will use the public key to authenticate the user who has the corresponding private key (id_rsa). This will allow the user to log in without entering a password. The

  other options are incorrect because they are either private keys (id_rsa, id_dsa.pem, or id_ecdsa) or non-existent files (id_dsa.pem or id_ecdsa). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13:

  Managing Network Services, page 410.

• Question 156:

  A systems administrator is tasked with changing the default shell of a system account in order to disable iterative logins. Which of the following is the best option for the administrator to use as the new shell?

  A. /sbin/nologin

  B. /bin/ sh

  C. /sbin/ setenforce

  D. /bin/bash

  Correct Answer: A

  The /sbin/nologin shell is a special shell that prevents the user from logging into an interactive session. It is commonly used for system accounts that are not meant to be accessed by users, such as daemon or service accounts. When a user

  tries to log in with this shell, they will see a message like "This account is currently not available" and the login will fail.

  References:

  The /sbin/nologin shell is listed as one of the valid shells in the /etc/shells file1. The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to "configure and manage system accounts and groups, including

  password aging and restricted shells" as part of the Hardware and System Configuration domain2.

  The usermod command can be used to change the user's login shell with the -s or --shell option3. For example, to change the shell of a user named daemon to /sbin/nologin, the command would be: sudo usermod -s /sbin/nologin daemon

• Question 157:

  A systems administrator is installing various software packages using a pack-age manager. Which of the following commands would the administrator use on the Linux server to install the package?

  A. winget

  B. softwareupdate

  C. yum-config

  D. apt

  Correct Answer: D

• Question 158:

  A Linux administrator needs to create a new cloud.cpio archive containing all the files from the current directory. Which of the following commands can help to accomplish this task?

  A. ls | cpio -iv > cloud.epio

  B. ls | cpio -iv < cloud.epio

  C. ls | cpio -ov > cloud.cpio

  D. ls cpio -ov < cloud.cpio

  Correct Answer: C

  Explanation: The command ls | cpio -ov > cloud.cpio can help to create a new cloud.cpio archive containing all the files from the current directory. The ls command lists the files in the current directory and outputs them to the standard output.

  The | operator pipes the output to the next command. The cpio command is a tool for creating and extracting compressed archives. The -o option creates a new archive and the -v option shows the verbose output. The > operator redirects the

  output to the cloud.cpio file. This command will create a new cloud.cpio archive with all the files from the current directory. The other options are incorrect because they either use the wrong options (-i instead of -o), the wrong arguments

  (cloud.epio instead of cloud.cpio), or the wrong syntax (< instead of > or missing |). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 11:

  Managing Files and Directories, page 351.

• Question 159:

  Employees in the finance department are having trouble accessing the file /opt/work/file. All IT employees can read and write the file. Systems administrator reviews the following output:

  

  Which of the following commands would permanently fix the access issue while limiting access to IT and finance department employees?

  A. chattr +i file

  B. chown it:finance file

  C. chmod 666 file

  D. setfacl -m g:finance:rw file

  Correct Answer: D

  Explanation: The command setfacl -m g:finance:rw file will permanently fix the access issue while limiting access to IT and finance department employees. The setfacl command is a tool for modifying the access control lists (ACLs) of files and

  directories on Linux systems. The ACLs are a mechanism that allows more fine-grained control over the permissions of files and directories than the traditional owner-group-others model. The - m option specifies the modification to the ACL.

  The g:finance:rw means that the group named finance will have read and write permissions on the file. The file is the name of the file to modify, in this case /opt/work/file. The command setfacl -m g:finance:rw file will add an entry to the ACL of

  the file that will grant read and write access to the finance group. This will fix the access issue and allow the finance employees to access the file. The command will also preserve the existing permissions of the file, which means that the IT

  employees will still have read and write access to the file. This will limit the access to IT and finance department employees and prevent unauthorized access from other users. This is the correct command to use to accomplish the task. The

  other options are incorrect because they either do not fix the access issue (chattr +i file or chown it:finance file) or do not limit the access to IT and finance department employees (chmod 666 file). References: CompTIA Linux+ (XK0-005)

  Certification Study Guide, Chapter 11:

  Managing File Permissions and Ownership, page 352.

• Question 160:

  A systems administrator needs to reconfigure a Linux server to allow persistent IPv4 packet forwarding. Which of the following commands is the correct way to accomplish this task?

  A. echo 1 > /proc/sys/net/ipv4/ipv_forward

  B. sysctl -w net.ipv4.ip_forward=1

  C. firewall-cmd --enable ipv4_forwarding

  D. systemct1 start ipv4_forwarding

  Correct Answer: B

  Explanation: The command sysctl -w net.ipv4.ip_forward=1 enables IPv4 packet forwarding temporarily by setting the kernel parameter net.ipv4.ip_forward to 1. To make this change persistent, the administrator needs to edit the file /etc/ sysctl.conf and add the line net.ipv4.ip_forward = 1. The other options are incorrect because they either use the wrong file (/proc/sys/net/ipv4/ipv_forward), the wrong command (firewall- cmd or systemct1), or the wrong option (--enable or start). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 12: Managing Network Connections, page 378.