Practice Free 102-500 Exam Online Questions
Question #41
Which of the following protocols is designed to access the video card output of a virtual machine?
- A . KDE
- B . X11
- C . Xfce
- D . SPICE
- E . XDMCP
Correct Answer: D
Question #42
What is the conventional purpose of Linux UIDs that are lower than 100?
- A . They are reserved for super user accounts.
- B . They are reserved for the system admin accounts.
- C . They are reserved for system accounts.
- D . They are unused, aside from 0, because they are targets of exploits.
- E . They are used to match with GIDs in grouping users.
Correct Answer: C
C
Explanation:
Linux UIDs (user identifiers) are numbers that are used to identify users and groups on a Linux system. Each user and group has a unique UID and GID (group identifier) respectively. The UID 0 is always reserved for the root or superuser account, which has full privileges to access and modify the system. The UIDs lower than 100 (or 1000 on some modern systems) are typically reserved for system accounts, which are used by various services and daemons that run on the system. These accounts are not meant for human users, but for specific purposes such as managing files, processes, network, security, etc. For example, some common system accounts are bin, daemon, mail, sshd, etc. The UIDs higher than 100 (or 1000) are usually allocated for regular user accounts, which have limited privileges and can be created and deleted by the system administrator. The system accounts are defined in the /etc/passwd file, which contains the username, UID, GID, home directory, shell, and other information for each account12345.
Reference: 1: Linux User Management – Tecmint 2: What are the well-known UIDs? – Stack Overflow 3: user ID less than 1000 on CentOS 7 – Unix & Linux Stack Exchange 4: Recommended GID for users group in Linux (100 or 1000)? – Unix & Linux Stack Exchange 5: What is the conventional purpose of Linux UIDs that are lower than 100? – VCE Guide
C
Explanation:
Linux UIDs (user identifiers) are numbers that are used to identify users and groups on a Linux system. Each user and group has a unique UID and GID (group identifier) respectively. The UID 0 is always reserved for the root or superuser account, which has full privileges to access and modify the system. The UIDs lower than 100 (or 1000 on some modern systems) are typically reserved for system accounts, which are used by various services and daemons that run on the system. These accounts are not meant for human users, but for specific purposes such as managing files, processes, network, security, etc. For example, some common system accounts are bin, daemon, mail, sshd, etc. The UIDs higher than 100 (or 1000) are usually allocated for regular user accounts, which have limited privileges and can be created and deleted by the system administrator. The system accounts are defined in the /etc/passwd file, which contains the username, UID, GID, home directory, shell, and other information for each account12345.
Reference: 1: Linux User Management – Tecmint 2: What are the well-known UIDs? – Stack Overflow 3: user ID less than 1000 on CentOS 7 – Unix & Linux Stack Exchange 4: Recommended GID for users group in Linux (100 or 1000)? – Unix & Linux Stack Exchange 5: What is the conventional purpose of Linux UIDs that are lower than 100? – VCE Guide
Question #43
Which commands can be used to change a user’s account aging information? (Choose THREE correct answers.)
- A . usermod
- B . passwd
- C . chattr
- D . chage
- E . chsh
Correct Answer: A, B, D
A, B, D
Explanation:
The usermod, passwd, and chage commands can be used to change a user’s account aging information. These commands can modify the password expiry date, the last password change date, the minimum and maximum number of days between password changes, the number of days of warning before password expiration, and the number of days of inactivity after password expiration. The usermod command is mainly used for modifying a user account, but it also has options for changing the password expiry and aging information, such as -e, -f, -p, and -L1. The passwd command is mainly used for changing the user password, but it also has options for changing the password expiry and aging information, such as -e, -i, -n, -w, and -x2. The chage command is specifically used for changing the user password expiry and aging information, and it has options such as -d, -E, -I, -m, -M, and -W3.
The other options, chattr and chsh, are not related to changing the user’s account aging information. The chattr command is used to change the file attributes on a Linux file system4. The chsh command is used to change the user’s login shell5.
Reference: usermod(8) ― Linux manual page
passwd(1) ― Linux manual page
chage(1) ― Linux manual page
chattr(1) ― Linux manual page
chsh(1) ― Linux manual page
A, B, D
Explanation:
The usermod, passwd, and chage commands can be used to change a user’s account aging information. These commands can modify the password expiry date, the last password change date, the minimum and maximum number of days between password changes, the number of days of warning before password expiration, and the number of days of inactivity after password expiration. The usermod command is mainly used for modifying a user account, but it also has options for changing the password expiry and aging information, such as -e, -f, -p, and -L1. The passwd command is mainly used for changing the user password, but it also has options for changing the password expiry and aging information, such as -e, -i, -n, -w, and -x2. The chage command is specifically used for changing the user password expiry and aging information, and it has options such as -d, -E, -I, -m, -M, and -W3.
The other options, chattr and chsh, are not related to changing the user’s account aging information. The chattr command is used to change the file attributes on a Linux file system4. The chsh command is used to change the user’s login shell5.
Reference: usermod(8) ― Linux manual page
passwd(1) ― Linux manual page
chage(1) ― Linux manual page
chattr(1) ― Linux manual page
chsh(1) ― Linux manual page
Question #44
Which of the following can the chage command NOT change?
- A . The number of days since January 1, 1970 after which the user’s account will no longer be accessible.
- B . The number of days since January 1, 1970 after which the password can change.
- C . The number of days since January 1, 1970 since the password was last changed.
- D . The maximum number of days during which a password is valid.
- E . The number of days of inactivity after a password has expired before the account is locked.
Correct Answer: E
E
Explanation:
The chage command can change the following parameters related to user password expiry and aging:
The last password change date (-d or –lastday option)
The password expiry date (-E or –expiredate option)
The minimum number of days between password changes (-m or –mindays option)
The maximum number of days during which a password is valid (-M or –maxdays option)
The number of days of warning before password expires (-W or –warndays option)
The chage command cannot change the number of days of inactivity after a password has expired before the account is locked. This parameter is controlled by the -I or –inactive option of the usermod command, which modifies the user account information. The chage command only displays the current value of this parameter, but does not allow changing it.
Reference: chage command in Linux with examples – GeeksforGeeks
10 chage command examples in Linux [Cheat Sheet] – GoLinuxCloud How to Use the Chage Command in Linux C TecAdmin
How to Manage User Password Expiration and Aging in Linux – Tecmint
E
Explanation:
The chage command can change the following parameters related to user password expiry and aging:
The last password change date (-d or –lastday option)
The password expiry date (-E or –expiredate option)
The minimum number of days between password changes (-m or –mindays option)
The maximum number of days during which a password is valid (-M or –maxdays option)
The number of days of warning before password expires (-W or –warndays option)
The chage command cannot change the number of days of inactivity after a password has expired before the account is locked. This parameter is controlled by the -I or –inactive option of the usermod command, which modifies the user account information. The chage command only displays the current value of this parameter, but does not allow changing it.
Reference: chage command in Linux with examples – GeeksforGeeks
10 chage command examples in Linux [Cheat Sheet] – GoLinuxCloud How to Use the Chage Command in Linux C TecAdmin
How to Manage User Password Expiration and Aging in Linux – Tecmint
Question #45
A user was not given permission to use the CRON scheduling system.
What file needs to be modified to provide that access? (Please specify the full path to the file)
Correct Answer: /etc/cron.allow
Explanation:
The /etc/cron.d/cron.allow file is a text file that contains the names of the users who are allowed to use the crontab command to create and manage their own cron jobs12. If this file exists, only the users listed in it can use the crontab command, and all other users are denied access12. If this file does not exist, the /etc/cron.d/cron.deny file is checked to see which users are not allowed to use the crontab command12. If neither file exists, only the root user can use the crontab command12. To modify the /etc/cron.d/cron.allow file, the root user can use any text editor to add or remove the names of the users who will be allowed to use the crontab command1234. For example, to allow the user frank to use the crontab command, the root user can append the name frank to
the /etc/cron.d/cron.allow file1234. The root user must always be included in this file, otherwise the superuser access to the crontab command will be denied4.
Reference: 1: Linux At, Batch, Atq, Atrm Command Help and Examples – Computer Hope 2: 107.2
Lesson 1 – Linux Professional Institute Certification Programs 3: /etc/cron.allow – Linux Bash Shell Scripting Tutorial Wiki – nixCraft 4: Controlling Access to crontab (System Administration Guide … – Oracle
Explanation:
The /etc/cron.d/cron.allow file is a text file that contains the names of the users who are allowed to use the crontab command to create and manage their own cron jobs12. If this file exists, only the users listed in it can use the crontab command, and all other users are denied access12. If this file does not exist, the /etc/cron.d/cron.deny file is checked to see which users are not allowed to use the crontab command12. If neither file exists, only the root user can use the crontab command12. To modify the /etc/cron.d/cron.allow file, the root user can use any text editor to add or remove the names of the users who will be allowed to use the crontab command1234. For example, to allow the user frank to use the crontab command, the root user can append the name frank to
the /etc/cron.d/cron.allow file1234. The root user must always be included in this file, otherwise the superuser access to the crontab command will be denied4.
Reference: 1: Linux At, Batch, Atq, Atrm Command Help and Examples – Computer Hope 2: 107.2
Lesson 1 – Linux Professional Institute Certification Programs 3: /etc/cron.allow – Linux Bash Shell Scripting Tutorial Wiki – nixCraft 4: Controlling Access to crontab (System Administration Guide … – Oracle
Question #46
How many IP-addresses can be used for unique hosts inside the IPv4 subnet 192.168.2.128/28? (Specify the number only without any additional information.)
Correct Answer: 14
Explanation:
To find the number of IP-addresses that can be used for unique hosts inside an IPv4 subnet, we need to calculate the number of bits that are used for the host part of the IP address. The host part is the part that is not used for the network prefix, which is indicated by the slash notation (/) followed by a number. The number after the slash represents the number of bits that are used for the network prefix, out of the total 32 bits of an IPv4 address. The remaining bits are used for the host part. For example, in the subnet 192.168.2.128/28, the number 28 means that the first 28 bits are used for the network prefix, and the last 4 bits are used for the host part.
The number of IP-addresses that can be used for unique hosts is equal to 2^n – 2, where n is the number of bits in the host part. The -2 is because the first and the last IP addresses in a subnet are reserved for the network address and the broadcast address, respectively, and cannot be assigned to hosts. Therefore, in the subnet 192.168.2.128/28, the number of IP-addresses that can be used for unique hosts is 2^4 – 2, which is 14.
Reference: IPv4 – Subnetting – Online Tutorials Library
IP Subnet Calculator
Explanation:
To find the number of IP-addresses that can be used for unique hosts inside an IPv4 subnet, we need to calculate the number of bits that are used for the host part of the IP address. The host part is the part that is not used for the network prefix, which is indicated by the slash notation (/) followed by a number. The number after the slash represents the number of bits that are used for the network prefix, out of the total 32 bits of an IPv4 address. The remaining bits are used for the host part. For example, in the subnet 192.168.2.128/28, the number 28 means that the first 28 bits are used for the network prefix, and the last 4 bits are used for the host part.
The number of IP-addresses that can be used for unique hosts is equal to 2^n – 2, where n is the number of bits in the host part. The -2 is because the first and the last IP addresses in a subnet are reserved for the network address and the broadcast address, respectively, and cannot be assigned to hosts. Therefore, in the subnet 192.168.2.128/28, the number of IP-addresses that can be used for unique hosts is 2^4 – 2, which is 14.
Reference: IPv4 – Subnetting – Online Tutorials Library
IP Subnet Calculator
Question #47
Which of the following commands display the number of bytes transmitted and received via the etho network interface? (Choose TWO correct answers.)
- A . Route Cv via etho
- B . Ip stats show dev etho
- C . Netstat Cs CI etho
- D . Ifconfig etho
- E . Ip Cs link show etho
Correct Answer: DE
Question #48
Which of the following parameters are used for journalctl to limit the time frame of the output? (Choose TWO correct answers.)
- A . –from=
- B . –since=
- C . –until=
- D . –upto=
- E . –date=
Correct Answer: B, C
B, C
Explanation:
The journalctl command is a tool for viewing and filtering the systemd journal logs. It accepts various parameters to control the output format, the source of the logs, and the filtering criteria. Two of the parameters that are used to limit the time frame of the output are –since= and –until=. These parameters take a date and time value in the format of “YYYY-MM-DD hh:mm:ss” or a relative value such as “-1h” for one hour ago. For example, the command journalctl –since="2023-11-22 23:00:00" –until="2023-11-23 00:00:00" will show the logs from 11:00 PM to 12:00 AM on November 22, 2023. The –since= and –until= parameters are part of the LPI’s multi-level Linux professional certification program, and they are covered in the topic 106.1 System logging of the exam 102 objectives1.
Reference: 1: https://www.lpi.org/our-certifications/exam-102-objectives/
B, C
Explanation:
The journalctl command is a tool for viewing and filtering the systemd journal logs. It accepts various parameters to control the output format, the source of the logs, and the filtering criteria. Two of the parameters that are used to limit the time frame of the output are –since= and –until=. These parameters take a date and time value in the format of “YYYY-MM-DD hh:mm:ss” or a relative value such as “-1h” for one hour ago. For example, the command journalctl –since="2023-11-22 23:00:00" –until="2023-11-23 00:00:00" will show the logs from 11:00 PM to 12:00 AM on November 22, 2023. The –since= and –until= parameters are part of the LPI’s multi-level Linux professional certification program, and they are covered in the topic 106.1 System logging of the exam 102 objectives1.
Reference: 1: https://www.lpi.org/our-certifications/exam-102-objectives/
Question #49
Which TWO statements about crontab are true?
- A . Every user may have their own crontab.
- B . Changing a crontab requires a reload/restart of the cron daemon.
- C . The cron daemon reloads crontab files automatically when necessary.
- D . hourly is the same as "0 * * * *".
- E . A cron daemon must run for each existing crontab.
Correct Answer: AC
AC
Explanation:
AC
Explanation:
Question #50
Which of the following keywords can be used in the file /etc/resolv.conf? (Choose TWO correct answers.)
- A . substitute
- B . nameserver
- C . search
- D . lookup
- E . method
Correct Answer: B, C
B, C
Explanation:
The file /etc/resolv.conf is the configuration file for the DNS resolver, which translates domain names to IP addresses by querying the DNS servers. The file supports several keywords that provide various types of resolver information. Two of the keywords that can be used in /etc/resolv.conf are: nameserver: This keyword specifies the IP address of the DNS server that the resolver can query against. Up to three nameservers can be configured, and the resolver will try them in order until one responds or all fail.
search: This keyword specifies a list of search domains that the resolver will append to the domain name when performing a query. For example, if the search list is example.com example.net, and the resolver queries for host, it will try host.example.com and host.example.net in order. The search list can have up to six domains, with a maximum of 256 characters in total.
The other keywords in the question are not valid for /etc/resolv.conf. The file does not support any keywords for substitution, lookup, or method.
However, there are other keywords that can be used, such as:
domain: This keyword specifies the local domain name of the system. It is mutually exclusive with the search keyword, and only one instance of either can be used.
options: This keyword specifies various options that modify the behavior of the resolver. For example, the option rotate can be used to rotate the nameservers in a round-robin fashion, instead of trying them in order. Multiple options can be specified, separated by spaces.
Reference: 3: The /etc/resolv.conf File | Baeldung on Linux
1: /etc/resolv.conf – QNX
4: Chapter 33. Manually configuring the /etc/resolv.conf file
B, C
Explanation:
The file /etc/resolv.conf is the configuration file for the DNS resolver, which translates domain names to IP addresses by querying the DNS servers. The file supports several keywords that provide various types of resolver information. Two of the keywords that can be used in /etc/resolv.conf are: nameserver: This keyword specifies the IP address of the DNS server that the resolver can query against. Up to three nameservers can be configured, and the resolver will try them in order until one responds or all fail.
search: This keyword specifies a list of search domains that the resolver will append to the domain name when performing a query. For example, if the search list is example.com example.net, and the resolver queries for host, it will try host.example.com and host.example.net in order. The search list can have up to six domains, with a maximum of 256 characters in total.
The other keywords in the question are not valid for /etc/resolv.conf. The file does not support any keywords for substitution, lookup, or method.
However, there are other keywords that can be used, such as:
domain: This keyword specifies the local domain name of the system. It is mutually exclusive with the search keyword, and only one instance of either can be used.
options: This keyword specifies various options that modify the behavior of the resolver. For example, the option rotate can be used to rotate the nameservers in a round-robin fashion, instead of trying them in order. Multiple options can be specified, separated by spaces.
Reference: 3: The /etc/resolv.conf File | Baeldung on Linux
1: /etc/resolv.conf – QNX
4: Chapter 33. Manually configuring the /etc/resolv.conf file