102-500試験無料問題集「Lpi LPIC-1 Exam 102, Part 2 of 2, version 5.0 認定」
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.)
正解：
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.
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.)
正解：
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 the name of the simple graphical login manager that comes with a vanilla X11 installation? (Specify ONLY the command without any path or parameters.)
正解：
xdm
Explanation:
The name of the simple graphical login manager that comes with a vanilla X11 installation is xdm. XDM is the traditional graphical login manager for the X Window System, independent of any window manager or environment the user might choose. When it is run at system startup, it displays a graphical login prompt rather than the text-based login prompt at the console1. XDM is part of the xorg-x11-apps package, which provides the basic applications for the X Window System2. XDM is also one of the topics covered by the LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops3. Reference:
xorg-x11-apps - Linux Man Pages (1) - SysTutorials
LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops GitHub - iwamatsu/slim: SLiM (Simple Login Manager) is a graphical login manager for X11 slim-fork download | SourceForge.net Using the XDM Graphical Login Manager | FreeBSD 6 Unleashed - Flylib Xorg - ArchWiki How to remotely log in with full graphical desktop over X11 - Unix & Linux Stack Exchange
Explanation:
The name of the simple graphical login manager that comes with a vanilla X11 installation is xdm. XDM is the traditional graphical login manager for the X Window System, independent of any window manager or environment the user might choose. When it is run at system startup, it displays a graphical login prompt rather than the text-based login prompt at the console1. XDM is part of the xorg-x11-apps package, which provides the basic applications for the X Window System2. XDM is also one of the topics covered by the LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops3. Reference:
xorg-x11-apps - Linux Man Pages (1) - SysTutorials
LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops GitHub - iwamatsu/slim: SLiM (Simple Login Manager) is a graphical login manager for X11 slim-fork download | SourceForge.net Using the XDM Graphical Login Manager | FreeBSD 6 Unleashed - Flylib Xorg - ArchWiki How to remotely log in with full graphical desktop over X11 - Unix & Linux Stack Exchange
Which port is the default server port for the HTTPS protocol? (Specify the port number using digits.)
正解：
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
Which parameter of the ssh command specifies the location of the private key used for login attempts? (Specify ONLY the option name without any values or parameters.)
正解：
sshkeygen