CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 81:

  A Linux administrator is configuring a new internal web server fleet. The web servers are up and running but can only be reached by users directly via IP address. The administrator is attempting to fix this inconvenience by requesting appropriate records from the DNS team. The details are: Hostname: devel.comptia.org

  IP address: 5.5.5.1, 5.5.5.2, 5.5.5.3, 5.5.5.4

  Name server: 5.5.5.254

  Additional names: dev.comptia.org, development.comptia.org

  Which of the following types of DNS records should the Linux administrator request from the DNS team? (Select three).

  A. MX

  B. NS

  C. PTR

  D. A

  E. CNAME

  F. RRSIG

  G. SOA

  H. TXT

  I. SRV

  Correct Answer: BDE

  The Linux administrator should request the following types of DNS records from the DNS team:

  A: This record type is used to map a hostname to an IPv4 address. The administrator needs four A records for devel.comptia.org, one for each IP address (5.5.5.1, 5.5.5.2, 5.5.5.3, 5.5.5.4). This will allow users to access the web servers by using the hostname devel.comptia.org instead of the IP addresses1. CNAME: This record type is used to create an alias for another hostname. The administrator needs two CNAME records, one for dev.comptia.org and one for development.comptia.org, both pointing to devel.comptia.org. This will allow users to access the web servers by using any of these three hostnames interchangeably1. NS: This record type is used to delegate a domain or a subdomain to another name server. The administrator needs one NS record for comptia.org, pointing to 5.5.5.254, which is the name server that hosts the records for the subdomain devel.comptia.org2. This will allow users to resolve the hostnames under comptia.org by querying the name server 5.5.5.2542. The other record types are not relevant for the administrator's task: MX: This record type is used to specify the mail exchange server for a domain or a subdomain1. The administrator does not need this record type because the web servers are not intended to handle email traffic. PTR: This record type is used to map an IP address to a hostname, which is the reverse of an A record1. The administrator does not need this record type because the web servers are not expected to be accessed by their IP addresses. RRSIG: This record type is used to provide digital signatures for DNSSEC, which is a security extension for DNS that verifies the authenticity and integrity of DNS responses3. The administrator does not need this record type because it is not mentioned in the task requirements. SOA: This record type is used to provide information about the authoritative name server and other parameters for a domain or a subdomain1. The administrator does not need this record type because it is usually created automatically by the name server software when a new zone file is created4. TXT: This record type is used to store arbitrary text data that can be used for various purposes, such as SPF, DKIM, DMARC, etc1. The administrator does not need this record type because it is not related to the web server functionality. SRV: This record type is used to specify the location and port number of a service that runs on a domain or a subdomain1. The administrator does not need this record type because the web servers use the standard HTTP port 80, which does not require an SRV record. References: 1: DNS Record Types ?CompTIA Network+ N10-007 ?1.8 2: NS Record - DNSimple Help 3: DNSSEC - Wikipedia 4: SOA Record - DNSimple Help

• Question 82:

  A Linux administrator is alerted to a storage capacity issue on a server without a specific mount point or directory. Which of the following commands would be MOST helpful for troubleshooting? (Choose two.)

  A. parted

  B. df

  C. mount

  D. du

  E. fdisk

  F. dd

  G. ls

  Correct Answer: BD

  Explanation: To troubleshoot a storage capacity issue on a server without a specific mount point or directory, two commands that would be most helpful are df and du. The df command displays information about disk space usage on all mounted filesystems, including their size, used space, available space, and percentage of usage. The du command displays disk space usage by files and directories in a given path, which can help identify large files or directories that may be taking up too much space. The other commands are incorrect because they either do not show disk space usage, or they are used for other purposes such as partitioning, formatting, checking, mounting, copying, or listing files. References: CompTIA Linux+ Study Guide, Fourth Edition, page 417-419.

• Question 83:

  A Linux administrator has physically added a new RAID adapter to a system. Which of the following commands should the Linux administrator run to confirm that the device has been recognized? (Select TWO).

  A. rmmod

  B. Is -11 /etc

  C. Ishw --class disk

  D. pvdisplay

  E. rmdir /dev

  F. dmesg

  Correct Answer: CF

  The following commands can help you confirm that the new RAID adapter has been recognized by the Linux system:

  dmesg: This command displays the kernel messages, which can show the information about the newly detected hardware device. You can use dmesg | grep -i raid to filter the output for RAID-related messages. lshw -class disk: This

  command lists the disk devices on the system, including the RAID controller and its model name. You can use lshw -class disk | grep -i raid to filter the output for RAID-related information1.

  The other commands are not relevant for this purpose. For example:

  rmmod: This command removes a module from the Linux kernel, which is not useful for detecting a new device.

  ls -l /etc: This command lists the files and directories in the /etc directory, which is not related to hardware devices.

  pvdisplay: This command displays the attributes of physical volumes, which are part of the logical volume management (LVM) system, not the RAID system. rmdir /dev: This command removes an empty directory, which is not helpful for

  detecting a new device. Moreover, /dev is a special directory that contains device files, and should not be removed.

• Question 84:

  A non-privileged user is attempting to use commands that require elevated account permissions, but the commands are not successful. Which of the following most likely needs to be updated?

  A. /etc/passwd

  B. /etc/shadow

  C. /etc/sudoers

  D. /etc/bashrc

  Correct Answer: C

  The /etc/sudoers file is used to configure the sudo command, which allows non-privileged users to execute commands that require elevated account permissions1. The file contains a list of users and groups that are allowed to use sudo, and

  the commands they can run with it. The file also defines the security policy for sudo, such as whether a password is required, how long the sudo session lasts, and what environment variables are preserved or reset.

  The /etc/passwd file is used to store information about the user accounts on the system, such as their username, user ID, home directory, and login shell. The /etc/shadow file is used to store the encrypted passwords for the user accounts,

  along with other information such as password expiration and aging. These files are not directly related to the sudo command, and updating them will not grant a user elevated account permissions. The /etc/bashrc file is used to set up the

  environment for the bash shell, such as aliases, functions, variables, and options. This file is executed whenever a new bash shell is started, and it affects all users on the system. However, this file does not control the sudo command or its

  configuration, and updating it will not allow a user to use commands that require elevated account permissions.

• Question 85:

  In which of the following filesystems are system logs commonly stored?

  A. /var

  B. /tmp

  C. /etc

  D. /opt

  Correct Answer: A

  Explanation: The filesystem that system logs are commonly stored in is /var. The /var filesystem is a directory that contains variable data files on Linux systems. Variable data files are files that are expected to grow in size over time, such as logs, caches, spools, and temporary files. The /var filesystem is separate from the / filesystem, which contains the essential system files, to prevent the / filesystem from being filled up by the variable data files. The system logs are files that record the events and activities of the system and its components, such as the kernel, the services, the applications, and the users. The system logs are useful for monitoring, troubleshooting, and auditing the system. The system logs are commonly stored in the /var/log directory, which is a subdirectory of the /var filesystem. The /var/log directory contains various log files, such as syslog, messages, dmesg, auth.log, and kern.log. The filesystem that system logs are commonly stored in is /var. This is the correct answer to the question. The other options are incorrect because they are not the filesystems that system logs are commonly stored in (/tmp, /etc, or /opt). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 16: Managing Logging and Monitoring, page 487.

• Question 86:

  An administrator recently updated the BIND software package and would like to review the default configuration that shipped with this version. Which of the following files should the administrator review?

  A. /etc/named.conf.rpmnew

  B. /etc/named.conf.rpmsave

  C. /etc/named.conf

  D. /etc/bind/bind.conf

  Correct Answer: A

  Explanation: After installing a new version of a package that includes a configuration file that already exists on the system, such as /etc/httpd/conf/httpd.conf, RPM will create a new file with the .rpmnew extension instead of overwriting the existing file. This allows the administrator to review the default configuration that shipped with this version and compare it with the current configuration before deciding whether to merge or replace the files. The /etc/named.conf.rpmsave file is created by RPM when a package is uninstalled and it contains a configuration file that was modified by the administrator. This allows the administrator to restore the configuration file if needed. The /etc/named.conf file is the main configuration file for the BIND name server, not the httpd web server. The /etc/bind/bind.conf file does not exist by default in Linux systems. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Packages and Software, page 561.

• Question 87:

  A Linux administrator is tasked with creating resources using containerization. When deciding how to create this type of deployment, the administrator identifies some key features, including portability, high availability, and scalability in production. Which of the following should the Linux administrator choose for the new design?

  A. Docker

  B. On-premises systems

  C. Cloud-based systems

  D. Kubernetes

  Correct Answer: D

  Explanation: The Linux administrator should choose Kubernetes for the new design that requires portability, high availability, and scalability in production using containerization. Kubernetes is an open-source platform that automates the deployment, scaling, and management of containerized applications across clusters of nodes. Kubernetes provides features such as service discovery, load balancing, storage orchestration, self-healing, secret and configuration management, and batch execution. Kubernetes also supports multiple container runtimes, such as Docker, containerd, and CRI-O, making it portable across different platforms and clouds. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Automating Tasks; What is Kubernetes? | Kubernetes

• Question 88:

  After starting an Apache web server, the administrator receives the following error:

  Apr 23 localhost.localdomain httpd 4618] : (98) Address already in use: AH00072: make_sock: could not bind to address [: :]80

  Which of the following commands should the administrator use to further trou-bleshoot this issue?

  A. Ss

  B. Ip

  C. Dig

  D. Nc

  Correct Answer: A

  The ss command is used to display information about socket connections, such as the port number, state, and process ID. The error message indicates that the port 80 is already in use by another process, which prevents the Apache web server from binding to it. By using the ss command with the -l and -n options, the administrator can list all the listening sockets and their port numbers in numeric form, and identify which process is using the port 80. For example: ss -ln | grep :80. The ip, dig, and nc commands are not relevant for this issue, as they are used for different purposes, such as configuring network interfaces, querying DNS records, and testing network connectivity.

• Question 89:

  A Linux administrator wants to find out whether files from the wget package have been altered since they were installed. Which of the following commands will provide the correct information?

  A. rpm -i wget

  B. rpm -qf wget

  C. rpm -F wget

  D. rpm -V wget

  Correct Answer: D

  Explanation: The command that will provide the correct information about whether files from the wget package have been altered since they were installed is rpm -V wget. This command will use the rpm utility to verify an installed RPM package by comparing information about the installed files with information from the RPM database. The verification process can check various attributes of each file, such as size, mode, owner, group, checksum, capabilities, and so on. If any discrepancies are found, rpm will report them using a single letter code for each attribute. The other options are not correct commands for verifying an installed RPM package. The rpm -i wget command is invalid because -i is used to install a package from a file, not to verify an installed package. The rpm -qf wget command will query which package owns wget as a file name or path name, but it will not verify its attributes. The rpm -F wget command will freshen (upgrade) an already installed package with wget as a file name or path name, but it will not verify its attributes. References: rpm(8) - Linux manual page; Using RPM to Verify Installed Packages

• Question 90:

  A junior developer is unable to access an application server and receives the following output:

  

  The systems administrator investigates the issue and receives the following output:

  

  Which of the following commands will help unlock the account?

  A. Pam_tally2 --user=dev2 ---quiet

  B. pam_ tally2 --user=dev2

  C. pam_tally2 --user+dev2 ---quiet

  D. pam_tally2 --user=dev2 ---reset

  Correct Answer: D

  To unlock an account that has been locked due to login failures, the administrator can use the command pam_tally2 --user=dev2 --reset (D). This will reset the failure counter for the user "dev2" and allow the user to log in again. The other

  commands will not unlock the account, but either display or increase the failure count. References:

  [CompTIA Linux+ Study Guide], Chapter 4: Managing Users and Groups, Section:

  Locking Accounts with pam_tally2

  [How to Lock and Unlock User Account in Linux]