Question 1

A Linux engineer needs to block an incoming connection from the IP address 2.2.2.2 to a secure shell
server and ensure the originating IP address receives a response that a firewall is blocking the
connection. Which of the following commands can be used to accomplish this task?

Accepted Answer

C

Explanation: The REJECT target sends back an error packet to the source IP address, indicating that the connection is refused by the firewall. This is different from the DROP target, which silently discards the packet without any response. The RETURN target returns to the previous chain, which may or may not accept the connection. The QUEUE target passes the packet to a userspace application for further processing, which is not the desired outcome in this case. CompTIA Linux+ (XK0-005) Certification Study Guide, page 316 iptables - ssh - access from specific ip only - Server Fault, answer by Eugene Ionichev

Question 2

A systems administrator identifies multiple processes in a zombie state. Which of the following signals would be best for the administrator to send to the PPID?

Accepted Answer

A

Explanation: A zombie process is a process that has completed execution but still has an entry in the process table because its parent process has not read its exit status. The best signal to send to the parent process is SIGTERM, which politely asks it to terminate and release the resources held by the zombie child processes.

Question 3

An administrator made a change to a system's network configuration. Which of the following best represents what the administrator should do to have the new configuration take effect?

Accepted Answer

A

Explanation: Step-by-Step Comprehensive Detailed Command systemctl restart networkd restarts the network service to apply changes. The networkd service is responsible for managing network configurations in systems using systemd-networkd. Why Other Options are Incorrect: B: Enables the service to start on boot but does not apply immediate changes. C: Displays the status but does not apply changes. D: isolate changes the target (runlevel) and does not directly affect network configurations. : CompTIA Linux+ Study Guide, Chapter on Networking Services man systemctl

Question 4

Which of the following can reduce the attack surface area in relation to Linux hardening?

Accepted Answer

B

Explanation: :

Question 5

A Linux administrator needs to check extended permissions applied to the directory test. Which of the following commands should the administrator use to help with this task?

Accepted Answer

C

Explanation: getfacl is the command used to view the Access Control List (ACL) of a file or directory, which shows extended permissions beyond the basic owner, group, and others. This is essential for checking permissions that are set using ACLs on the directory test.

Question 6

A Linux systems administrator is updating code. After completing the update, the administrator
wants to publish the updated code without including the configuration files. Which of the following
should the administrator use to accomplish this task?

Accepted Answer

C

Explanation: The .gitignore file is used in Git to specify which files or directories should be ignored in a repository. By listing configuration files in the .gitignore file, the administrator ensures they are not included in any future commits or pushes to the remote repository. This is essential when dealing with sensitive or environment-specific files that should not be shared or deployed. Reference: Git Documentation on .gitignore

Question 7

An operations engineer is planning to start a container running a PostgreSQL database. The engineer
wants the container to start automatically at system startup, mount the /home/db directory as
/var/lib/postgresql inside the container, and expose port 5432 to the OS. Which of the following
commands should the engineer run to achieve this task?

Accepted Answer

A

Explanation: The command docker run -d --restart always -p 5432:5432 -v /home/db:/var/lib/postgresql postgresql:12 ensures that the PostgreSQL container is started in detached mode (-d), it restarts automatically on system startup (--restart always), mounts the host directory /home/db to /var/lib/postgresql, and exposes port 5432. This is a typical setup for running a database in a Docker container.

Question 8

A file called testfile has both uppercase and lowercase letters:

$ cat testfile ABCDEfgH IJKLmnoPQ abcdefgH ijklLMNopq

A Linux administrator is tasked with converting testfile into all uppercase and writing it to a new file with the name uppercase.

Which of the following commands will achieve this task?

Accepted Answer

D

Explanation: This command will use the tr tool to translate all lowercase letters in the testfile to uppercase letters and write the output to the uppercase file. The first argument ‘[a-z]’ specifies the set of characters to be replaced, and the second argument ‘[A-Z]’ specifies the set of characters to replace with. The ‘<’ symbol redirects the input from the testfile, and the ‘>’ symbol redirects the output to the uppercase file12. : 1: Linux Tr Command - javatpoint 2: Linux tr Command with Examples - phoenixNAP

Question 9

A systems administrator created a user cron to run a scheduled database backup cronjob on the
server at 1 a.m. every day. The following is the cronjob syntax:
0 1 * * * /bin/sh backup.sh
The backups, however, are not being created. When checking the crontab file, the administrator sees
the following error:
/var/spool/cron/crontab/cron: Permission denied
Which of the following will permit the cronjob to execute?

Accepted Answer

A

Explanation: The error indicates that the cron user does not have permission to run the cronjob. Creating a cron.allow file and adding the user cron to it will allow that user to run cronjobs. The cron.allow file is a security feature that controls which users are allowed to use cron.

Question 10

An administrator is investigating why a Linux workstation is not resolving a website. The output of dig and nslookup shows that IPv4 resolution is working, but IPv6 resolution fails.

The administrator executes: nslookup -querytype=AAAA www.comptia.org Can't find www.comptia.org: No answer The workstation has a static entry in /etc/hosts: 104.18.99.101 www.comptia.org

Which of the following is the most likely cause?

Accepted Answer

A

Explanation: The presence of a static entry in /etc/hosts for www.comptia.org forces the system to use this IP address instead of querying DNS. This prevents proper IPv6 (AAAA) resolution, as /etc/hosts only contains an IPv4 (A) record. Removing this static entry allows the system to query DNS for both IPv4 and IPv6 records. : Linux /etc/hosts File – Linux Documentation

Question 11

A diagnostic tool reports a "host seems down" event for a server with an IP address of 192.168.47.44. Which of the following commands should the administrator use to confirm the host down event?

Accepted Answer

D

Explanation: The ping -c 1 192.168.47.44 command sends one ICMP echo request to the specified host to check its availability. If the host is down, there will be no response. This is the quickest way to confirm if a host is reachable. nmap -Pn can also be used to check a host status, but ping is faster and lighter.

Question 12

A systems administrator is configuring a Linux system so the network traffic from the internal network 172.17.0.0/16 going out through the eth0 interface would appear as if it was sent directly from this interface. Which of the following commands will accomplish this task?

Accepted Answer

A

Explanation: This command will use the iptables tool to append a rule to the POSTROUTING chain of the nat table, which will match any packet with a source address of 172.17.0.0/16 and an output interface of eth0, and apply the MASQUERADE target to it. This means that the packet will have its source address changed to the address of the eth0 interface, effectively hiding the internal network behind a NAT12. : 1: Iptables NAT and Masquerade rules - what do they do? 2: Routing from docker containers using a different physical network interface and default gateway

Question 13

DRAG DROP As a Systems Administrator, to reduce disk space, you were tasked to create a shell script that does the following: Add relevant content to /tmp/script.sh, so that it finds and compresses rotated files in /var/log without recursion. INSTRUCTIONS Fill the blanks to build a script that performs the actual compression of rotated log files. If at any time you would like to bring back the initial state of the simulation, please click the Reset All button. https://kxbjsyuhceggsyvxdkof.supabase.co/storage/v1/object/public/file-images/Linux+_XK0-005/page_6_img_1.jpg

Accepted Answer

Answer available on page.

Question 14

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.

Accepted Answer

Answer available on page.

Question 15

HOTSPOT
A new drive was recently added to a Linux system. Using the environment and tokens provided,
complete the following tasks:
• Create an appropriate device label.
• Format and create an ext4 file system on the new partition.
The current working directory is /.
XK0-005 practice exam questions

Accepted Answer

HTTPS://KXBJSYUHCEGGSYVXDKOF.SUPABASE.CO/STORAGE/V1/OBJECT/PUBLIC/FILE-IMAGES/LINUX+_XK0-005/PAGE_145_IMG_1.JPG

Explanation: https://kxbjsyuhceggsyvxdkof.supabase.co/storage/v1/object/public/file-images/Linux+_XK0-005/page_145_img_1.jpg To create an appropriate device label, format and create an ext4 file system on the new partition, you can use the following commands: To create a GPT (GUID Partition Table) label on the new drive /dev/sdc, you can use the parted command with the -s option (for script mode), the device name (/dev/sdc), the mklabel command, and the label type (gpt). The command is: parted -s /dev/sdc mklabel gpt To create a primary partition of 10 GB on the new drive /dev/sdc, you can use the parted command with the -s option, the device name (/dev/sdc), the mkpart command, the partition type (primary), the file system type (ext4), and the start and end points of the partition (1 and 10G). The command is: parted -s /dev/sdc mkpart primary ext4 1 10G To format and create an ext4 file system on the new partition /dev/sdc1, you can use the mkfs command with the file system type (ext4) and the device name (/dev/sdc1). The command is: mkfs.ext4 /dev/sdc1 You can verify that the new partition and file system have been created by using the lsblk command, which will list all block devices and their properties.

Free COMPTIA Linux+ XK0-005 Actual Exam Questions