최신 102-500 무료덤프 - Lpi LPIC-1 Exam 102, Part 2 of 2, version 5.0
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.)
정답:
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
What is pool.ntp.org?
정답: D
설명: (DumpTOP 회원만 볼 수 있음)
Which port is the default server port for the HTTPS protocol? (Specify the port number using digits.)
정답:
443
Explanation:
The port number 443 is the default server port for the HTTPS protocol, which is a secure version of HTTP that uses SSL/TLS certificates to encrypt the data transmission between web servers and browsers. The port number 443 is recognized by the Internet Engineering Task Force (IETF) as the standard port for HTTPS connections1. The port number 443 is part of the topic 109.1: Fundamentals of internet protocols, which is one of the objectives of the LPI Linux Administrator - 102 exam23. Reference: 1: HTTPS Port: What It Is, How to Use It, and More (2023) - Hostinger 2: LPI Linux Administrator - 102 (LPIC-1) 3: Exam 102 Objectives
Explanation:
The port number 443 is the default server port for the HTTPS protocol, which is a secure version of HTTP that uses SSL/TLS certificates to encrypt the data transmission between web servers and browsers. The port number 443 is recognized by the Internet Engineering Task Force (IETF) as the standard port for HTTPS connections1. The port number 443 is part of the topic 109.1: Fundamentals of internet protocols, which is one of the objectives of the LPI Linux Administrator - 102 exam23. Reference: 1: HTTPS Port: What It Is, How to Use It, and More (2023) - Hostinger 2: LPI Linux Administrator - 102 (LPIC-1) 3: Exam 102 Objectives
You need to pause the CUPS printer HPLaserjet4, and you want to cancel all print jobs with a message, "hello". Which command will do this?
정답: D
설명: (DumpTOP 회원만 볼 수 있음)
Which file, if present, must contain all users that are allowed to use the cron scheduling system? (Specify the full name of the file, including path.)
정답:
crontab
Explanation:
The file /etc/cron.allow, if present, must contain all users that are allowed to use the cron scheduling system. This file is used to restrict the access to cron for security reasons. Only users listed in this file can create and edit their own crontab files using the crontab command. If the file does not exist, all users can use cron, unless the file /etc/cron.deny exists, which lists the users that are not allowed to use cron12. Reference: 1: Cron and Crontab usage and examples. 2: How to use cron in Linux.
Explanation:
The file /etc/cron.allow, if present, must contain all users that are allowed to use the cron scheduling system. This file is used to restrict the access to cron for security reasons. Only users listed in this file can create and edit their own crontab files using the crontab command. If the file does not exist, all users can use cron, unless the file /etc/cron.deny exists, which lists the users that are not allowed to use cron12. Reference: 1: Cron and Crontab usage and examples. 2: How to use cron in Linux.
In which file, if present, must all users be listed that are allowed to use the cron scheduling system? (Specify the full name of the file, including path.)
정답:
etccronallow
Explanation:
The /etc/cron.allow file is a file that contains a list of users who are allowed to use the cron scheduling system. The cron scheduling system is a way of running commands or scripts at specified times or intervals. Users can create their own cron jobs by using the crontab command, which edits a file called crontab that stores the user's scheduled tasks. However, not all users may have access to the crontab command or the cron system. The access is controlled by two files: /etc/cron.allow and /etc/cron.deny. If the /etc/cron.allow file exists, then only the users listed in this file can use the crontab command and the cron system. The file should have one user name per line. If the /etc/cron.allow file does not exist, then the /etc/cron.deny file is checked. If this file exists, then the users listed in this file are denied access to the crontab command and the cron system. If neither file exists, then the access depends on the configuration of the cron daemon, which is the program that runs the cron jobs. By default, only the root user can use the cron system if no files exist. The root user can always use the cron system regardless of the existence or content of these files. To create or edit the /etc/cron.allow file, the root user needs to use a text editor such as vi, nano, or emacs. For example, to allow the users alice and bob to use the cron system, the root user can use the following command:
sudo vi /etc/cron.allow
And then add the following lines to the file:
alice bob
And then save and exit the file. Reference:
How cron.allow and cron.deny can be used to limit access to crontab for ...
/etc/cron.allow - Linux Bash Shell Scripting Tutorial Wiki
Linux / UNIX Restrict at / cron Usage To Authorized Users
Explanation:
The /etc/cron.allow file is a file that contains a list of users who are allowed to use the cron scheduling system. The cron scheduling system is a way of running commands or scripts at specified times or intervals. Users can create their own cron jobs by using the crontab command, which edits a file called crontab that stores the user's scheduled tasks. However, not all users may have access to the crontab command or the cron system. The access is controlled by two files: /etc/cron.allow and /etc/cron.deny. If the /etc/cron.allow file exists, then only the users listed in this file can use the crontab command and the cron system. The file should have one user name per line. If the /etc/cron.allow file does not exist, then the /etc/cron.deny file is checked. If this file exists, then the users listed in this file are denied access to the crontab command and the cron system. If neither file exists, then the access depends on the configuration of the cron daemon, which is the program that runs the cron jobs. By default, only the root user can use the cron system if no files exist. The root user can always use the cron system regardless of the existence or content of these files. To create or edit the /etc/cron.allow file, the root user needs to use a text editor such as vi, nano, or emacs. For example, to allow the users alice and bob to use the cron system, the root user can use the following command:
sudo vi /etc/cron.allow
And then add the following lines to the file:
alice bob
And then save and exit the file. Reference:
How cron.allow and cron.deny can be used to limit access to crontab for ...
/etc/cron.allow - Linux Bash Shell Scripting Tutorial Wiki
Linux / UNIX Restrict at / cron Usage To Authorized Users
On a system using system-journald, which of the following command add the message Howdy to the system log? (Choose two correct answers.)
정답: C,D
On a Linux system with shadow passwords enabled, which file in the file system contains the password hashes of all local users? (Specify the full name of the file, including path.)
정답:
etcshadow
Explanation:
On a Linux system with shadow passwords enabled, the file that contains the password hashes of all local users is /etc/shadow. This file is a replacement for the password field in /etc/passwd, which is a world-readable file that contains basic information about users. The /etc/shadow file is not readable by regular users, and it stores the encrypted passwords (or hashes) of each user, along with other information such as password expiration dates, minimum and maximum password ages, and password warning periods. The /etc/shadow file has nine colon-delimited fields for each user:
Username: The name used when the user logs into the system.
Password: The encrypted password of the user, or a special character that indicates the password status. For example, an asterisk (*) means the account is locked, and an exclamation mark (!) means the password is expired.
Last Password Change: The date of the last password change, expressed as the number of days since January 1, 1970.
Minimum Password Age: The minimum number of days required between password changes. A zero means the password can be changed anytime.
Maximum Password Age: The maximum number of days the password is valid. After this number of days, the password must be changed. A zero means the password never expires.
Password Warning Period: The number of days before the password expires that the user will be warned. A zero means no warning is given.
Password Inactivity Period: The number of days after the password expires that the account will be disabled. A negative value means the account is never disabled.
Account Expiration Date: The date when the account will be disabled, expressed as the number of days since January 1, 1970. A zero means the account never expires.
Reserved Field: A field for future use.
The /etc/shadow file can be modified by using the commands passwd and chage, which are used to change the password and the password aging information of a user, respectively. The /etc/shadow file should not be edited directly, but always through the tools provided by the distribution. For more details, see the shadow manual page.
Reference:
LPIC-1 Exam 102 Objectives, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Weight: 2, Key Knowledge Areas: Configure sudo and sudoers. Use sudo to execute commands as another user.
LPIC-1 Exam 102 Learning Materials, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Section 110.2.1: sudo and sudoers, Page 3-5.
Explanation:
On a Linux system with shadow passwords enabled, the file that contains the password hashes of all local users is /etc/shadow. This file is a replacement for the password field in /etc/passwd, which is a world-readable file that contains basic information about users. The /etc/shadow file is not readable by regular users, and it stores the encrypted passwords (or hashes) of each user, along with other information such as password expiration dates, minimum and maximum password ages, and password warning periods. The /etc/shadow file has nine colon-delimited fields for each user:
Username: The name used when the user logs into the system.
Password: The encrypted password of the user, or a special character that indicates the password status. For example, an asterisk (*) means the account is locked, and an exclamation mark (!) means the password is expired.
Last Password Change: The date of the last password change, expressed as the number of days since January 1, 1970.
Minimum Password Age: The minimum number of days required between password changes. A zero means the password can be changed anytime.
Maximum Password Age: The maximum number of days the password is valid. After this number of days, the password must be changed. A zero means the password never expires.
Password Warning Period: The number of days before the password expires that the user will be warned. A zero means no warning is given.
Password Inactivity Period: The number of days after the password expires that the account will be disabled. A negative value means the account is never disabled.
Account Expiration Date: The date when the account will be disabled, expressed as the number of days since January 1, 1970. A zero means the account never expires.
Reserved Field: A field for future use.
The /etc/shadow file can be modified by using the commands passwd and chage, which are used to change the password and the password aging information of a user, respectively. The /etc/shadow file should not be edited directly, but always through the tools provided by the distribution. For more details, see the shadow manual page.
Reference:
LPIC-1 Exam 102 Objectives, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Weight: 2, Key Knowledge Areas: Configure sudo and sudoers. Use sudo to execute commands as another user.
LPIC-1 Exam 102 Learning Materials, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Section 110.2.1: sudo and sudoers, Page 3-5.
When trying to unmount a device it is reported as being busy. Which of the following commands could be used to determine which process is causing this?
정답: C
설명: (DumpTOP 회원만 볼 수 있음)
What is true regarding TCP port 23?
정답: D
설명: (DumpTOP 회원만 볼 수 있음)
Which of the following options in the chrony configuration file define remote lime sources? (Choose TWO correct answers.)
정답: A,E
Which of the following configuration files should be modified to set default shell variables for all users?
정답: C
설명: (DumpTOP 회원만 볼 수 있음)