CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 101:

  DRAG DROP

  You have been asked to parse a log file of logins to determine various information about who is logging in and when.

  INSTRUCTIONS

  Open and inspect the Login log file.

  Drag and drop the correct commands onto the output that was generated from that

  command.

  Tokens can be used only once and not all will be used.

  If at any time you would like to bring back the initial state of the simulation, please click the Reset All button.

  Select and Place:

  

  Correct Answer:

  

• Question 102:

  An administrator would like to securely connect to a server and forward port 8080 on a local machine to port 80 on the server. Which of the following commands should the administrator use to satisfy both requirements?

  A. ssh --L 8080: localhost:80 admin@server

  B. ssh --R 8080: localhost:80 admin@server

  C. ssh --L 80 : localhost:8080 admin@server

  D. ssh --R 80 : localhost:8080 admin@server

  Correct Answer: A

  This command will create a local port forwarding, which means that connections from the SSH client are forwarded via the SSH server, then to a destination server. In this case, the destination server is the same as the SSH server (localhost),

  and the destination port is 80. The SSH client will listen on port 8080 on the local machine, and any connection to that port will be forwarded to port 80 on the server. This way, the administrator can securely access the web service running on

  port 80 on the server by using http://localhost:8080 on the local machine.

  The other options are incorrect because:

  B. ssh -R 8080:localhost:80 admin@server

  This command will create a remote port forwarding, which means that connections from the SSH server are forwarded via the SSH client, then to a destination server. In this case, the destination server is the same as the SSH client

  (localhost), and the destination port is 80. The SSH server will listen on port 8080 on the remote machine, and any connection to that port will be forwarded to port 80 on the client. This is not what the administrator wants to do.

  C. ssh -L 80:localhost:8080 admin@server

  This command will also create a local port forwarding, but it will use port 80 on the local machine and port 8080 on the server. This is not what the administrator wants to do, and it may also fail if port 80 is already in use by another service on

  the local machine.

  D. ssh -R admin@server

  This command is incomplete and invalid. It does not specify any port numbers or destination addresses for the remote port forwarding. It will also fail if the SSH server does not allow remote port forwarding.

  References:

  CompTIA Linux+ Certification Exam Objectives

  How to Set up SSH Tunneling (Port Forwarding)

• Question 103:

  A junior systems administrator recently installed an HBA card in one of the servers that is deployed for a production environment. Which of the following commands can the administrator use to confirm on which server the card was installed?

  A. lspci | egrep 'hba| fibr'

  B. lspci | zgrep 'hba | fibr'

  C. lspci | pgrep 'hba| fibr'

  D. lspci | 'hba | fibr'

  Correct Answer: A

  The best command to use to confirm on which server the HBA card was installed is A. lspci | egrep `hba| fibr'. This command will list all the PCI devices on the server and filter the output for those that match the pattern `hba' or `fibr', which are likely to be related to the HBA card. The egrep command is a variant of grep that supports extended regular expressions, which allow the use of the `|' operator for alternation. The other commands are either invalid or will not produce the desired output. For example:

  B. lspci | zgrep `hba | fibr' will try to use zgrep, which is a command for searching compressed files, not standard output.

  C. lspci | pgrep `hba| fibr' will try to use pgrep, which is a command for finding processes by name or other attributes, not text patterns. D. lspci | `hba | fibr' will try to use `hba | fibr' as a command, which is not valid and will cause an error.

• Question 104:

  A systems administrator is compiling a report containing information about processes that are listening on the network ports of a Linux server. Which of the following commands will allow the administrator to obtain the needed information?

  A. ss -pint

  B. tcpdump -nL

  C. netstat -pn

  D. lsof -It

  Correct Answer: A

  Explanation: The command ss -pint will allow the administrator to obtain the needed information about processes that are listening on the network ports of a Linux server. The ss command is a tool for displaying socket statistics on Linux systems. Sockets are endpoints of network communication that allow processes to exchange data over the network. The ss command can show various information about the sockets, such as the state, address, port, protocol, and process. The -pint option specifies the filters and flags that the ss command should apply. The -p option shows the process name and ID that owns the socket. The -i option shows the internal information about the socket, such as the send and receive queue, the congestion window, and the retransmission timeout. The - n option shows the numerical address and port, instead of resolving the hostnames and service names. The -t option shows only the TCP sockets, which are the most common type of sockets used for network communication. The command ss -pint will display the socket statistics for the TCP sockets, along with the process name and ID, the numerical address and port, and the internal information. This will allow the administrator to obtain the needed information about processes that are listening on the network ports of a Linux server. This is the correct command to use to obtain the needed information. The other options are incorrect because they either do not show the socket statistics (tcpdump - nL or lsof -It) or do not show the process name and ID (netstat -pn). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 12: Managing Network Connections, page 389.

• Question 105:

  A Linux administrator is adding a new configuration file to a Git repository. Which of the following describes the correct order of Git commands to accomplish the task successfully?

  A. pull -> push -> add -> checkout

  B. pull -> add -> commit -> push

  C. checkout -> push -> add -> pull

  D. pull -> add -> push -> commit

  Correct Answer: B

  Explanation: The correct order of Git commands to add a new configuration file to a Git repository is pull -> add -> commit -> push. The pull command will fetch and merge the changes from the remote repository to the local repository, ensuring that the local repository is up to date. The add command will stage the new configuration file for the next commit, marking it as a new file to be tracked by Git. The commit command will create a new snapshot of the project state with the new configuration file and a descriptive message. The push command will publish the commit to the remote repository, updating the remote branch with the new configuration file. The pull -> push -> add -> checkout order is incorrect, as it will not create a commit for the new configuration file, and it will switch to a different branch without pushing the changes. The checkout -> push -> add -> pull order is incorrect, as it will switch to a different branch before adding the new configuration file, and it will overwrite the local changes with the remote changes without creating a commit. The pull -> add -> push -> commit order is incorrect, as it will not create a commit before pushing the changes, and it will create a commit that is not synchronized with the remote branch. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 20: Writing and Executing Bash Shell Scripts, page 579.

• Question 106:

  Due to performance issues on a server, a Linux administrator needs to termi-nate an unresponsive process. Which of the following commands should the administrator use to terminate the process immediately without waiting for a graceful shutdown?

  A. kill -SIGKILL 5545

  B. kill -SIGTERM 5545

  C. kill -SIGHUP 5545

  D. kill -SIGINT 5545

  Correct Answer: A

  To terminate an unresponsive process immediately without waiting for a graceful shutdown, the administrator can use the command kill -SIGKILL 5545 (A). This will send a signal to the process with the PID 5545 that cannot be ignored or

  handled by the process, and force it to stop. The other commands will send different signals that may allow the process to perform some cleanup or termination actions, or may be ignored by the process.

  References:

  [CompTIA Linux+ Study Guide], Chapter 6: Managing Processes, Section: Killing Processes

  [How to Kill Processes in Linux]

• Question 107:

  A systems administrator is adding a Linux-based server and removing a Windows-based server from a cloud-based environment. The changes need to be validated before they are applied to the cloud-based environment. Which of the following tools should be used to meet this requirement?

  A. Ansible

  B. git clone

  C. git pull

  D. terraform plan

  Correct Answer: D

  Terraform is a tool for building, changing, and managing infrastructure as code in a cloud- based environment. Terraform uses configuration files to describe the desired state of the infrastructure and applies changes accordingly. Terraform

  supports various cloud providers, such as AWS, Azure, Google Cloud Platform, and more. To validate changes before they are applied to the cloud-based environment, the administrator can use the terraform plan command. This command

  will compare the current state of the infrastructure with the desired state defined in the configuration files and show what actions will be performed to achieve the desired state. This command will not make any changes to the infrastructure but

  only show a plan of changes. The statement D is correct.

  The statements A, B, and C are incorrect because they do not validate changes before they are applied to the cloud-based environment. Ansible is another tool for automating infrastructure management, but it does not have a plan command.

  Git clone and git pull are commands for working with git repositories, which are used for version control of code. References: [How to Use Terraform to Manage Cloud Infrastructure]

• Question 108:

  A Linux systems administrator is setting up a new web server and getting 404 - NOT FOUND errors while trying to access the web server pages from the browser. While working on the diagnosis of this issue, the Linux systems administrator executes the following commands:

  

  Which of the following commands will BEST resolve this issue?

  A. sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config

  B. restorecon -R -v /var/www/html

  C. setenforce 0

  D. setsebool -P httpd_can_network_connect_db on

  Correct Answer: B

  Explanation: The command restorecon -R -v /var/www/html will best resolve the issue. The issue is caused by the incorrect SELinux context of the web server files under the /var/www/html directory. The output of ls -Z /var/www/html shows that the files have the type user_home_t, which is not allowed for web content. The command restorecon restores the default SELinux context of files based on the policy rules. The options -R and -v are used to apply the command recursively and verbosely. This command will change the type of the files to httpd_sys_content_t, which is the correct type for web content. This will allow the web server to access the files and serve the pages to the browser. The other options are incorrect because they either disable SELinux entirely (sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config or setenforce 0), which is not a good security practice, or enable an unnecessary boolean (setsebool -P httpd_can_network_connect_db on), which is not related to the issue. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Securing Linux Systems, page 535.

• Question 109:

  A systems administrator is tasked with mounting a USB drive on a system. The USB drive has a single partition, and it has been mapped by the system to the device /dev/sdb. Which of the following commands will mount the USB to /media/ usb?

  A. mount /dev/sdb1 /media/usb

  B. mount /dev/sdb0 /media/usb

  C. mount /dev/sdb /media/usb

  D. mount -t usb /dev/sdb1 /media/usb

  Correct Answer: A

  Explanation: The mount /dev/sdb1 /media/usb command will mount the USB drive to /media/usb. This command will attach the filesystem on the first partition of the USB drive (/dev/sdb1) to the mount point /media/usb, making it accessible to

  the system. The mount /dev/sdb0 /media/usb command is invalid, as there is no such device as /dev/sdb0. The mount /dev/sdb /media/usb command is incorrect, as it will try to mount the entire USB drive instead of its partition, which may

  cause errors or data loss. The mount -t usb /dev/sdb1 /media/usb command is incorrect, as usb is not a valid filesystem type for mount. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14:

  Managing Disk Storage, page 455.

• Question 110:

  A Linux administrator needs to transfer a local file named accounts . pdf to a remote / tmp directory of a server with the IP address 10.10.10.80. Which of the following commands needs to be executed to transfer this file?

  A. rsync [email protected]: /tmp accounts.pdf

  B. scp accounts.pdf [email protected]:/tmp

  C. cp [email protected]. 80: /tmp accounts.pdf

  D. ssh accounts.pdf [email protected]: /tmp

  Correct Answer: B

  The best command to use to transfer the local file accounts.pdf to the remote /tmp directory of the server with the IP address 10.10.10.80 is B. scp accounts.pdf [email protected]:/tmp. This command will use the secure copy protocol (scp) to

  copy the file from the local machine to the remote server over SSH. The command requires the username and password of the user on the remote server, as well as the full path of the destination directory.

  The other commands are either incorrect or not suitable for this task. For example:

  A. rsync [email protected]:/tmp accounts.pdf will try to use the rsync command to synchronize files between the local and remote machines, but it has the wrong syntax and order of arguments. The source should come before the destination, and a colon (:) should separate the remote host and path. C. cp [email protected]:/tmp accounts.pdf will try to use the cp command to copy files, but it does not work over SSH and it has the wrong syntax and order of arguments. The source should come before the destination, and a colon (:) should separate the remote host and path.

  D. ssh accounts.pdf [email protected]:/tmp will try to use the ssh command to log into the remote server, but it has the wrong syntax and arguments. The username should come before the remote host, and a file name is not a valid argument for ssh.