CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 321:

  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
  D. setfacl -m g:finance:rw file

  ---

  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 322:

  A systems administrator wants to permit access temporarily to an application running on port 1234/TCP on a Linux server. Which of the following commands will permit this traffic?

  A. firewall-cmd --new-service=1234/tcp
  B. firewall-cmd --service=1234 --protocol=tcp
  C. firewall-cmd --add--port=1234/tcp
  D. firewall-cmd --add-whitelist-uid=1234
  C. firewall-cmd --add--port=1234/tcp

  ---

  Explanation

  The firewall-cmd command is used to manage firewalld, which is a firewall service for Linux systems that provides dynamic and persistent configuration of firewall rules. Firewalld uses zones and services to define different levels of trust and access for network connections. To permit access temporarily to an application running on port 1234/TCP on a Linux server, the systems administrator can use the firewall-cmd --add-port=1234/tcp command. This command will add a rule to the default zone (usually public) that allows incoming traffic on port 1234/TCP. The rule will only be effective until the next reload or restart of firewalld. To make the rule permanent, the administrator can add the --permanent option to the command. The statement C is correct. The statements A, B, and D are incorrect because they do not permit access to port 1234/TCP. The firewall-cmd --new-service=1234/tcp command does not exist. The firewall- cmd --service=1234 --protocol=tcp command does not work because 1234 is not a predefined service name in firewalld. The firewall-cmd --add-whitelist-uid=1234 command does not exist.

  References: [How to Use FirewallD to Manage Firewall in Linux]

• Question 323:

  A developer needs to launch an Nginx image container, name it Web001, and ex-pose port 8080 externally while mapping to port 80 inside the container. Which of the following commands will accomplish this task?

  A. docker exec --it -p 8080: 80 ----name Web001 nginx
  B. docker load -it -p 8080:80 ----name Web001 nginx
  C. docker run -it -P 8080:80 ----name Web001 nginx
  D. docker pull -it -p 8080:80 --name Web00l nginx
  C. docker run -it -P 8080:80 ----name Web001 nginx

  ---

  Explanation

  To launch an Nginx image container, name it Web001, and expose port 8080 externally while mapping to port 80 inside the container, the administrator can use the command docker run -it -p 8080:80 --name Web001 nginx ? This will create

  and start a new container from the Nginx image, assign it a name of Web001, and map port 8080 on the host to port 80 on the container. The other commands are not valid or do not meet the requirements.

  References:

  [CompTIA Linux+ Study Guide], Chapter 11: Working with Containers, Section:

  Running Containers with Docker

  [How to Run Docker Containers]

• Question 324:

  A Linux administrator is configuring crontab and needs to schedule a task to run only on Saturday and Sunday at 9:00 a.m. every week of the year. Which of the following should the administrator use?

  A. 0 9 * * 1-5 root /root/script.sh
  B. 0 9 1 */3 * root /root/script.sh
  C. 0 9 * * 6,0 root /root/script.sh
  D. 0 9 1 * * root /root/script.sh
  C. 0 9 * * 6,0 root /root/script.sh

  ---

  Explanation

  0 9 * * 6,0 ensures execution at 9:00 AM on Saturdays (6) and Sundays (0).

  1-5 would run the script Monday-Friday.

  */3 is incorrect because it runs every three days.

  1 * * runs only on the 1st day of each month.

  CompTIA Linux+ Official Study Guide, Chapter on Job Scheduling and Cron

• Question 325:

  A systems administrator receives reports of issues in one of the Linux systems. The following output has been provided: $ dig node.mycomptia.org ; <<>> DiG 9.11.36 <<>> node.mycomptia.org ;; global options: +cmd ;; connection timed out; no servers could be reached $ cat /etc/resolv.conf search mycomptia.org Which of the following actions will best resolve this issue? (Select two.)

  A. echo "8.8.8.8 node.mycomptia.org" >> /etc/hosts
  B. echo "nameserver 8.8.8.8" >> /run/systemd/resolve/resolv.conf
  C. systemctl restart networkd
  D. echo "nameserver 8.8.8.8" >> /etc/resolv.conf
  E. echo "DNS1=8.8.8.8" >> /etc/sysconfig/network-scripts/ifcfg-eth0
  F. systemctl restart NetworkManager
  G. systemctl restart named
  D. echo "nameserver 8.8.8.8" >> /etc/resolv.conf
  F. systemctl restart NetworkManager

  ---

  Explanation

• Question 326:

  A systems administrator is deploying a web server using the following code:

  name "Web Server"

  description "The role contains nodes, which act as a web server"

  run_list "recipe[ntp]"

  default_attributes "ntp" => {

  "ntpdate" => {

  "disable" => true

  }

  }

  Which of the following technologies is the administrator using to create this web server?

  A. Chef
  B. Ansible
  C. Puppet
  D. Terraform
  A. Chef

  ---

  Explanation

• Question 327:

  A Linux administrator is investigating the reason a systemd timer is not running every night at midnight. The administrator sees the following unit file:

  [Unit]

  Description=Execute backup every day at midnight

  [Timer]

  OnCalendar=--01 00:00:00

  Unit=backup.service

  RandomizedDelaySec=10800

  [Install]

  WantedBy=multi-user.target

  Which of the following modifications should the administrator make in the unit file? (Select two).

  A. Remove RandomizedDelaySec=10800.
  B. Add WakeSystem=Midnight.
  C. Change OnCalendar to 00:00:00.
  D. Add OnCalendar=--* daily.
  E. Add AccuracySec=1.
  F. Remove OnCalendar=--01 00:00:00.
  A. Remove RandomizedDelaySec=10800.

  ---

  Explanation

  The RandomizedDelaySec parameter delays the timer by a random time within the specified seconds, which can be up to 3 hours in this case. Removing it will ensure the timer triggers at exactly midnight. Additionally, using OnCalendar=--*

  daily correctly schedules the timer to run every day at midnight.

  Systemd Timer Units

• Question 328:

  Which of the following directories contains binaries that only a root user should run?

  A. /sbin
  B. /bin
  C. /root
  D. /lib
  A. /sbin

  ---

  Explanation

  The /sbin directory contains essential system binaries that are typically only used by the root user. These binaries include commands like ifconfig, fdisk, and reboot, which require root privileges to execute. /bin contains user-level binaries, while /root is the home directory of the root user, and /lib holds shared libraries.

• Question 329:

  A user generated a pair of private-public keys on a workstation. Which of the following commands will allow the user to upload the public key to a remote server and enable passwordless login?

  A. scp ~/.ssh/id_rsa user@server:~/
  B. rsync ~ /.ssh/ user@server:~/
  C. ssh-add user server
  D. ssh-copy-id user@server
  D. ssh-copy-id user@server

  ---

  Explanation

  The command ssh-copy-id user@server will allow the user to upload the public key to a remote server and enable passwordless login. The ssh-copy-id command is a tool for copying the public key to a remote server and appending it to the authorized_keys file, which is used for public key authentication. The command will also set the appropriate permissions on the remote server to ensure the security of the key. The command ssh-copy-id user@server will copy the public key of the user to the server and allow the user to log in without a password. This is the correct command to use for this task. The other options are incorrect because they either do not copy the public key (scp, rsync, or ssh-add) or do not use the correct syntax (scp ~/.ssh/id_rsa user@server:~/ instead of scp ~/.ssh/id_rsa.pub user@server:~/ or rsync ~ /.ssh/ user@server:~/ instead of rsync ~/.ssh/id_rsa.pub user@server:~/).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 410.

• Question 330:

  A systems administrator frequently connects to a remote host via SSH and a non-standard port. The systems administrator would like to avoid passing the port parameter on the command line every time. Which of the following files can be used to set a different port value for that host?

  A. /etc/ssh/sshd_config
  B. /etc/ssh/moduli
  C. ~/.ssh/config
  D. ~/.ssh/authorized_keys
  C. ~/.ssh/config

  ---

  Explanation

  The ~/.ssh/config file can be used to set various options for SSH connections, including the port number, for specific hosts or groups of hosts. This file is located in the user's home directory and affects only the current user. The /etc/ssh/sshd_config file is used to configure the SSH server daemon, not the client. The /etc/ssh/moduli file contains parameters for Diffie-Hellman key exchange, not port settings. The ~/.ssh/authorized_keys file contains public keys for authentication, not port settings.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 12:

  Secure Shell (SSH), page 414.