CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 181:

  A Linux administrator is configuring a two-node cluster and needs to be able to connect the nodes to each other using SSH keys from the root account. Which of the following commands will accomplish this task?

  A. [root@nodea ssh --i ~/ . ssh/±d rsa root@nodeb

  B. [root@nodea scp -i . ssh/id rsa root@nodeb

  C. [root@nodea ssh--copy-id --i .ssh/id rsa root@nodeb

  D. [root@nodea # ssh add -c ~/ . ssh/id rsa root@nodeb

  E. [root@nodea # ssh add -c ~/. ssh/id rsa root@nodeb

  Correct Answer: C

  The ssh-copy-id command is used to copy a public SSH key from a local machine to a remote server and add it to the authorized_keys file, which allows passwordless authentication between the machines. The administrator can use this command to copy the root user's public key from nodea to nodeb, and vice versa, to enable SSH access between the nodes without entering a password every time. For example: [root@nodea ssh-copy-id -i ~/.ssh/id_rsa root@nodeb]. The ssh command is used to initiate an SSH connection to a remote server, but it does not copy any keys. The scp command is used to copy files securely between machines using SSH, but it does not add any keys to the authorized_keys file. The ssh-add command is used to add private keys to the SSH agent, which manages them for SSH authentication, but it does not copy any keys to a remote server.

• Question 182:

  Which of the following enables administrators to configure and enforce MFA on a Linux system?

  A. Kerberos

  B. SELinux

  C. PAM

  D. PKI

  Correct Answer: C

  Explanation: The mechanism that enables administrators to configure and enforce MFA on a Linux system is PAM. PAM stands for Pluggable Authentication Modules, which is a framework for managing authentication and authorization on Linux systems. PAM allows the administrator to define the rules and policies for accessing various system resources and services, such as login, sudo, ssh, or cron. PAM also supports different types of authentication methods, such as passwords, tokens, biometrics, or smart cards. PAM can be used to implement MFA, which stands for Multi-Factor Authentication, which is a security technique that requires the user to provide more than one piece of evidence to prove their identity. MFA can enhance the security of the system and prevent unauthorized access. PAM enables administrators to configure and enforce MFA on a Linux system. This is the correct answer to the question. The other options are incorrect because they either do not manage authentication and authorization on Linux systems (Kerberos or PKI) or do not support MFA (SELinux). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 17: Implementing Basic Security, page 517.

• Question 183:

  Which of the following would significantly help to reduce data loss if more than one drive fails at the same time?

  A. Server clustering

  B. Load balancing

  C. RAID

  D. VDI

  Correct Answer: C

  RAID stands for Redundant Array of Independent Disks, which is a technology that combines multiple physical disks into a logical unit that provides improved performance, reliability, or both. RAID can significantly help to reduce data loss if more than one drive fails at the same time, depending on the RAID level used. For example, RAID 1 (mirroring) duplicates the data on two or more disks, so that if one disk fails, the data can be recovered from another disk. RAID 5 (striping with parity) distributes the data and parity information across three or more disks, so that if one disk fails, the data can be reconstructed from the remaining disks. RAID 6 (striping with double parity) extends RAID 5 by adding another parity block, so that if two disks fail, the data can still be recovered from the remaining disks. References: [What is RAID?]

• Question 184:

  A systems administrator is checking the system logs. The administrator wants to look at the last 20 lines of a log. Which of the following will execute the command?

  A. tail -v 20

  B. tail -n 20

  C. tail -c 20

  D. tail -l 20

  Correct Answer: B

  Explanation: The command tail -n 20 will display the last 20 lines of a file. The -n option specifies the number of lines to show. This is the correct command to execute the task. The other options are incorrect because they either use the wrong options (-v, -c, or -l) or have the wrong arguments (20 instead of 20 filename). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 11: Managing Files and Directories, page 352.

• Question 185:

  Which of the following technologies can be used as a central repository of Linux users and groups?

  A. LDAP

  B. MFA

  C. SSO

  D. PAM

  Correct Answer: A

  Explanation: LDAP stands for Lightweight Directory Access Protocol, which is a protocol for accessing and managing a central directory of users and groups. LDAP can be used as a central repository of Linux users and groups, allowing for centralized authentication and authorization across multiple Linux systems. MFA, SSO, and PAM are not technologies that can be used as a central repository of Linux users and groups. MFA stands for Multi- Factor Authentication, which is a method of verifying a user's identity using more than one factor, such as a password, a token, or a biometric. SSO stands for Single Sign-On, which is a feature that allows a user to log in once and access multiple applications or systems without having to re-enter credentials. PAM stands for Pluggable Authentication Modules, which is a framework that allows Linux to use different authentication methods, such as passwords, tokens, or biometrics. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 8: Managing Users and Groups

• Question 186:

  A Linux administrator is troubleshooting SSH connection issues from one of the workstations.

  When users attempt to log in from the workstation to a server with the IP address 104.21.75.76, they receive the following message:

  

  The administrator reviews the information below:

  

  

  Which of the following is causing the connectivity issue?

  A. The workstation has the wrong IP settings.

  B. The sshd service is disabled.

  C. The server's firewall is preventing connections from being made.

  D. The server has an incorrect default gateway configuration.

  Correct Answer: C

  Explanation: The server's firewall is preventing connections from being made, which is causing the connectivity issue. The output of iptables -L -n shows that the firewall is blocking all incoming traffic on port 22, which is the default port for SSH. The output of ssh -v [email protected] shows that the connection is refused by the server. To resolve the issue, the administrator needs to allow port 22 on the firewall. The other options are incorrect because they are not supported by the outputs. The workstation has the correct IP settings, as shown by the output of ip addr show. The sshd service is enabled and running, as shown by the output of systemct1 status sshd. The server has the correct default gateway configuration, as shown by the output of ip route show. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, pages 406-407.

• Question 187:

  A Linux administrator is creating a new sudo profile for the accounting user. Which of the following should be added by the administrator to the sudo configuration file so that the accounting user can run / opt/ acc/ report as root?

  A. accounting localhost=/opt/acc/report

  B. accounting ALL=/opt/acc/report

  C. %accounting ALL=(ALL) NOPASSWD: /opt/acc/report

  D. accounting /opt/acc/report= (ALL) NOPASSWD: ALL

  Correct Answer: C

  This answer allows the accounting user to run the /opt/acc/report command as root on any host without entering a password. The % sign indicates that accounting is a group name, not a user name. The ALL keyword means any host, any

  user, and any command, depending on the context. The NOPASSWD tag overrides the default behavior of sudo, which is to ask for the user's password.

  The other answers are incorrect for the following reasons:

  A. accounting localhost=/opt/acc/report

  B. accounting ALL=/opt/acc/report

  D. accounting /opt/acc/report= (ALL) NOPASSWD: ALL

• Question 188:

  After installing some RPM packages, a systems administrator discovers the last package that was installed was not needed. Which of the following commands can be used to remove the package?

  A. dnf remove packagename

  B. apt-get remove packagename

  C. rpm -i packagename

  D. apt remove packagename

  Correct Answer: A

  Explanation: The command that can be used to remove an RPM package that was installed by mistake is dnf remove packagename. This command will use the DNF package manager to uninstall an RPM package and its dependencies from a Linux system that uses RPM-based distributions, such as Red Hat Enterprise Linux or CentOS. The DNF package manager handles dependency resolution and metadata searching for RPM packages. The other options are not correct commands for removing an RPM package from a Linux system. The apt-get remove packagename and apt remove packagename commands are used to remove Debian packages from a Linux system that uses Debian-based distributions, such as Ubuntu or Debian. They are not compatible with RPM packages. The rpm -i packagename command is used to install an RPM package, not to remove it. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 9: Managing Software Packages; How to install/remove/query/update RPM packages in Linux (Cheat Sheet ...

• Question 189:

  A user is asking the systems administrator for assistance with writing a script to verify whether a file exists. Given the following:

  

  Which of the following commands should replace the string?

  A. if [ -f "$filename" ]; then

  B. if [ -d "$filename" ]; then

  C. if [ -f "$filename" ] then

  D. if [ -f "$filename" ]; while

  Correct Answer: A

  Explanation: The command if [ -f "$filename" ]; then checks if the variable $filename refers to a regular file that exists. The -f option is used to test for files. If the condition is true, the commands after then are executed. This is the correct way to replace the string. The other options are incorrect because they either use the wrong option (-d tests for directories), the wrong syntax (missing a semicolon after the condition), or the wrong keyword (while is used for loops, not conditions). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter

  16: Writing and Executing Bash Shell Scripts, page 493.

• Question 190:

  At what point is the Internal Certificate Authority (ICA) created?

  A. During the primary Security Management Server installation process.

  B. Upon creation of a certificate.

  C. When an administrator decides to create one.

  D. When an administrator initially logs into SmartConsole.

  Correct Answer: A

  Explanation: The Internal Certificate Authority (ICA) is created during the primary Security Management Server installation process. The ICA is a component of Check Point's Public Key Infrastructure (PKI) that issues and manages certificates for Security Gateways and administrators. The ICA is automatically installed and initialized when the primary Security Management Server is installed. The ICA is not created upon creation of a certificate, when an administrator decides to create one, or when an administrator initially logs into SmartConsole. References: Check Point Certified Security Administrator (CCSA) R80.x Study Guide, Chapter 3: Check Point Security Management Architecture, page 32.