CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 201:

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

  ---

  Explanation

  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 202:

  A Linux administrator is configuring Apache on a system and needs to allow the service to start after every startup. Which of the following commands will allow the Linux administrator to accomplish this task while starting the service at the same time?

  A. systemctl mask --state=active httpd
  B. systemctl start --runtime boot httpd
  C. systemctl set-property restart httpd
  D. systemctl enable --now httpd
  D. systemctl enable --now httpd

  ---

  Explanation

• Question 203:

  An administrator would like to list all current containers, regardless of their running state. Which of the following commands would allow the administrator to accomplish this task?

  A. docker ps -a
  B. docker list
  C. docker image ls
  D. docker inspect image
  A. docker ps -a

  ---

  Explanation

  The best command to use to list all current containers, regardless of their running state, is A. docker ps -a. This command will show all containers, both running and stopped, with details such as container ID, image name, status, and ports. The other commands are either invalid or not relevant for this task. For example:

  B. docker list is not a valid command. There is no subcommand named list in docker.

  C. docker image ls will list all the images available on the local system, not the containers.

  D. docker inspect image will show detailed information about a specific image, not all the containers.

• Question 204:

  A Linux administrator attempts to log in to a server over SSH as root and receives the following error message: Permission denied, please try again. The administrator is able to log in to the console of the server directly with root and confirms the password is correct. The administrator reviews the configuration of the SSH service and gets the following output:

  

  Based on the above output, which of the following will most likely allow the administrator to log in over SSH to the server?

  A. Log out other user sessions because only one is allowed at a time.
  B. Enable PAM and configure the SSH module.
  C. Modify the SSH port to use 2222.
  D. Use a key to log in as root over SSH.
  D. Use a key to log in as root over SSH.

  ---

  Explanation

• Question 205:

  A systems administrator is receiving complaints about slow performance and system crashes. The administrator suspects memory and CPU issues. Which of the following is the first action the administrator should take to troubleshoot and resolve these issues?

  A. Run resource monitoring tools like top or htop to view the current CPU and memory use.
  B. Look through the system logs and error messages to find any faults involving the CPU and memory.
  C. Remove and replace the CPU and memory components to address hardware issues.
  D. Reboot the server to clear any CPU and memory congestion.
  A. Run resource monitoring tools like top or htop to view the current CPU and memory use.

  ---

  Explanation

  The initial troubleshooting step when experiencing slow performance and potential memory or CPU issues is to analyze the current resource usage. Running tools like top or htop allows the administrator to observe real-time data on CPU,

  memory, and processes, providing insights into high resource usage. This is a non-invasive first step, helping to identify whether issues are due to overuse, application memory leaks, or specific processes. CompTIA Linux+ recommends

  understanding system resource behavior before taking further action.

  CompTIA Linux+ Study Guide.

• Question 206:

  An administrator would like to mirror the website files on the primary web server, www1, to the backup web server, www2. Which of the following commands should the administrator use to most efficiently accomplish this task?

  A. [wwwl ] rsync --a --e ssh /var/www/html/ user1@www2 : /var/www/html
  B. [ wwwl ] scp --r /var/www/html user1@www2 : / var/www/html
  C. [www2 ] cd /var/www/html; wget --m http: //wwwl/
  D. [wwwl ] cd /var/www/html andand tar cvf -
  A. [wwwl ] rsync --a --e ssh /var/www/html/ user1@www2 : /var/www/html

  ---

  Explanation

  To mirror the website files on the primary web server, www1, to the backup web server, www2, the administrator can use the command rsync -a -e ssh /var/www/html/ user1@www2:/var/www/html (A). This will synchronize all files and directories under /var/www/html/ on www1 to /var/www/html on www2 using ssh as the remote shell. The -a option will preserve all attributes and permissions of the files. The other commands will not mirror the website files, but either copy them once, download them from a web server, or archive them.

  References: [CompTIA Linux+ Study Guide], Chapter 12: Troubleshooting Linux Systems, Section: Synchronizing Files with rsync [How to Use rsync Command in Linux]

• Question 207:

  A Linux administrator is troubleshooting an issue in which an application service failed to start on a Linux server. The administrator runs a few commands and gets the following outputs:

  

  Based on the above outputs, which of the following is the MOST likely action the administrator should take to resolve this issue?

  A. Enable the logsearch.service and restart the service.
  B. Increase the TimeoutStartUSec configuration for the logsearch.sevice.
  C. Update the OnCalendar configuration to schedule the start of the logsearch.service.
  D. Update the KillSignal configuration for the logsearch.service to use TERM.
  B. Increase the TimeoutStartUSec configuration for the logsearch.sevice.

  ---

  Explanation

  The administrator should increase the TimeoutStartUSec configuration for the logsearch.service to resolve the issue. The output of systemct1 status logsearch.service shows that the service failed to start due to a timeout. The output of cat / etc/systemd/system/logsearch.service shows that the service has a TimeoutStartUSec configuration of 10 seconds, which might be too short for the service to start. The administrator should increase this value to a higher number, such as 30 seconds or 1 minute, and then restart the service. The other options are incorrect because they are not related to the issue. The service is already enabled, as shown by the output of systemct1 is-enabled logsearch.service. The service does not use an OnCalendar configuration, as it is not a timer unit. The service does not use a KillSignal configuration, as it is not being killed by a signal.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Processes and Scheduling Tasks, pages 434-435.

• Question 208:

  A cloud engineer needs to check the link status of a network interface named eth1 in a Linux server. Which of the following commands can help to achieve the goal?

  A. ifconfig hw eth1
  B. netstat -r eth1
  C. ss -ti eth1
  D. ip link show eth1
  D. ip link show eth1

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  Explanation

  The ip link show eth1 command can be used to check the link status of a network interface named eth1 in a Linux server. It will display information such as the MAC address, MTU, state, and flags of the interface. The ifconfig hw eth1 command is invalid, as hw is not a valid option for ifconfig. The netstat -r eth1 command would display the routing table for eth1, not the link status. The ss -ti eth1 command would display TCP information for sockets associated with eth1, not the link status.

  References: CompTIA Linux+ (XK0- 005) Certification Study Guide, Chapter 13: Networking Fundamentals, page 436.

• Question 209:

  A Linux administrator created a virtual clone of a physical server and would like to remove any existing entries related to SSH keys from outside entities on the virtual clone. Which of the following files should the administrator remove? (Select two).

  A. ~/.ssh/authorized_keys
  B. ~/.ssh/known_hosts
  C. /etc/ssh/ssh_config
  D. ~/.ssh/config
  E. /etc/ssh/sshd_config
  F. /etc/ssh/ssh_host_rsa_key.pub
  A. ~/.ssh/authorized_keys
  B. ~/.ssh/known_hosts

  ---

  Explanation

  The ~/.ssh/authorized_keys file contains SSH public keys that grant access to the user account. Removing this file ensures that no external entities can log in using previously authorized keys. The ~/.ssh/known_hosts file stores fingerprints of previously connected hosts. Removing this file ensures that SSH doesn't trust any previously connected hosts.

• Question 210:

  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
  D. id_rsa.pub

  ---

  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.