LPI 010-160 Exam With Confidence Using Practice Dumps

The su command stands for substitute user or switch user. It allows you to run a shell or a command as another user, usually the superuser or root. To use the su command, you need to know the password of the target user. For example, if you want to switch to the root user, you can type su - and enter the root password. This will give you a root shell, where you can execute commands with administrative privileges. To exit the root shell, you can type exit or press Ctrl-D. The su command is not the default shell of the root account, nor can it only be used by the root user. It can be used by any user who knows the password of another user. The su command does not change the name of the main administrator account, which is always root on Linux systems. The su command also does not lock the root account in specific time frames, although there are other ways to do that, such as using the pam_time module. References:

• Linux Essentials - Linux Professional Institute (LPI), section 5.1.1
• LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition, chapter 9, page 219.

 In Linux, every file and directory is associated with an owner and a group. The owner is the user who created the file or directory, and the group is the group to which the owner belongs. Therefore, each file is owned by exactly one user and one group. This is true for option A. The other options are false for the following reasons:

• Option B: The owner of a file does not always have full permissions when accessing the file. The permissions are determined by the file mode, which can be changed by the owner or the root user. The file mode specifies the read, write, and execute permissions for the owner, the group, and others. The owner can have different permissions than the group or others.
• Option C: The user owning a file does not have to be a member of the file’s group. The owner can change the group ownership of the file to any group on the system, regardless of whether the owner belongs to that group or not. However, only the root user or a user with the CAP_CHOWN capability can change the group ownership to a group that the owner is not a member of.
• Option D: When a user is deleted, all files owned by the user do not disappear. The files remain on the system, but their owner is changed to an invalid user ID (UID). The files can still be accessed by the group or others, depending on the permissions. The files can also be reclaimed by the root user or a user with the CAP_CHOWN capability, who can change the owner to a valid user.
• Option E: The owner of a file can be changed once it is assigned to an owner. The owner can transfer the ownership to another user, or the root user or a user with the CAP_CHOWN capability can change the owner to any user on the system. The command to change the owner of a file is chown. References: 1: Chown Command in Linux (File Ownership) | Linuxize 2 3: Linux File Permissions and Ownership Explained with Examples 4 2: 3 Ways to Find File Owner in Linux - howtouselinux 1

DHCP stands for Dynamic Host Configuration Protocol. It is a protocol that provides quick, automatic, and central management for the distribution of IP addresses within a network. It also configures other network information, such as the subnet mask, default gateway, and DNS server information, on the device1. DHCP uses a client/server architecture, where a DHCP server issues unique IP addresses and automatically configures the devices that request them2. DHCP allows devices to move freely from one network to another and receive an IP address automatically, which is helpful with mobile devices1.

The other options are not protocols used for automatic IP address configuration. NFS stands for Network File System, which is a protocol that allows a user to access and modify files over a network as if they were on their own computer. LDAP stands for Lightweight Directory Access Protocol, which is a protocol that provides access to a centralized directory service that stores information about users, groups, computers, and other resources on a network. SMTP stands for Simple Mail Transfer Protocol, which is a protocol that enables the sending and receiving of email messages over a network. DNS stands for Domain Name System, which is a protocol that translates domain names into IP addresses and vice versa. References:

• Linux Essentials Exam Objectives, Version 1.6, Topic 105.1, Weight 4
• What Is DHCP? (Dynamic Host Configuration Protocol) - Lifewire
• Dynamic Host Configuration Protocol (DHCP) | Microsoft Learn
• Dynamic Host Configuration Protocol - Wikipedia
• How does AutoIP work? - Barix
• [Network File System - Wikipedia]
• [Lightweight Directory Access Protocol - Wikipedia]
• [Simple Mail Transfer Protocol - Wikipedia]
• [Domain Name System - Wikipedia]