LPI 102-500 LPIC-1 System Administrator Exam 102, Part 2 of 2, version 5.0 Exam Practice Test

Answer : A

The configuration file for the OpenSSH server is called sshd_config. It is typically located in /etc/ssh on most *NIX systems, but is /etc/sshd_config in the case of MacOS X and perhaps other systems. OpenSSH has two different sets of configuration files: one for client programs (ssh, scp, and sftp) and one for the server daemon (sshd).System-wide SSH configuration information is stored in the /etc/ssh/ directory1.Reference:1:Where is the configuration file for OpenSSH server?

Answer : A

Theidcommand will display the user ID (uid), the primary group ID (gid), and the supplementary groups (groups) of a user. The output will show the names and the numerical IDs of the groups. For example:

id linuxize

The command will show the user ID (uid), the user's primary group (gid), and the user's secondary groups (groups)

uid=1001(linuxize) gid=1001(linuxize) groups=1001(linuxize),27(sudo)

To print only the names instead of the numbers use the-noption.

id -nG linuxize

The command will show only the names of the groups

linuxize sudo

Theidcommand is part of the GNU coreutils package and is available on all Linux systems. The full path of the command is/usr/bin/id.Reference:

id(1) - Linux manual page

How to List Groups in Linux | Linuxize

Answer : D

The command systemctl list-timers shows all active systemd timers, which are units that can be used to schedule the execution of other units at specific times or after certain intervals. The output of the command includes the following columns:

NEXT: The next time the timer will trigger.

LEFT: The time left until the next trigger.

LAST: The last time the timer triggered.

PASSED: The time passed since the last trigger.

UNIT: The name of the timer unit.

ACTIVATES: The name of the unit that is activated by the timer.

For example, the following output shows two active timers: apt-daily.timer and apt-daily-upgrade.timer, which are used to perform automatic updates on Debian-based systems.

NEXT LEFT LAST PASSED UNIT ACTIVATES Mon 2021-11-15 06:00:00 UTC 9h left Sun 2021-11-14 06:00:01 UTC 20h ago apt-daily.timer apt-daily.service Mon 2021-11-15 06:23:51 UTC 9h left Sun 2021-11-14 06:23:51 UTC 20h ago apt-daily-upgrade.timer apt-daily-upgrade.service 2 timers listed.

The other commands in the options are either invalid or unrelated to systemd timers:

systemctl-timer show is not a valid command. To show the details of a specific timer unit, the command systemctl show unit.timer can be used, where unit is the name of the unit that is activated by the timer.

timectl list is not a valid command. To list the available time zones, the command timedatectl list-timezones can be used. To list the current time and date settings, the command timedatectl can be used without any arguments.

systemctl -t is not a complete command. To list all units of a specific type, the command systemctl -t type can be used, where type is the name of the unit type, such as service, timer, socket, etc.

timeq is not a valid command. It may be confused with the time command, which measures the time taken by a command or program to execute.

LPIC-1 Exam 102 Objectives, Topic 107: Administrative Tasks, Subtopic 107.2: Automate system administration tasks by scheduling jobs, Weight: 4, Key Knowledge Areas: Use cron and systemd timers to run jobs at regular intervals and to use anacron to manage system cron jobs. Objective: Use systemd timers to run jobs at regular intervals and to use anacron to manage system cron jobs.

LPIC-1 Exam 102 Learning Materials, Topic 107: Administrative Tasks, Subtopic 107.2: Automate system administration tasks by scheduling jobs, Section 107.2.3: systemd timers, Page 21-22.

Answer : C

The ulimit command can be used to limit the amount of memory a user may use. The ulimit command is a shell builtin that allows the user to view or modify the resource limits imposed by the operating system. The resource limits can affect the maximum size of files, the maximum number of processes, the maximum amount of CPU time, and the maximum amount of virtual memory a user can access.

To limit the amount of memory a user may use, the -v option can be used with the ulimit command. The -v option sets the maximum amount of virtual memory available to the current shell and its children in kilobytes. For example, the command ulimit -v 1000000 would limit the virtual memory to 1 GB. The -m option can also be used to set the maximum resident set size, which is the amount of physical memory used by a process, but this option is not supported by all systems.

The ulimit command can be used interactively in a shell session, or it can be placed in a shell initialization file, such as .bashrc or .profile, to apply the limits to all future shell sessions. The ulimit command can also be used in conjunction with the /etc/security/limits.conf file, which allows the system administrator to set global or per-user resource limits for all users and processes. The /etc/security/limits.conf file can specify hard and soft limits for each resource, as well as the scope of the limit, such as user, group, or domain.

The other commands listed are not related to limiting the amount of memory a user may use. The umask command sets the default file permissions for newly created files and directories. The usermod command modifies the user account information, such as the home directory, the login shell, or the password expiration date. The passwd command changes the user password. The chage command changes the password aging information, such as the minimum and maximum number of days between password changes, or the number of days before the password expires.Reference:

ulimit(1) - Linux manual page

How to limit user environment with ulimit Linux command

Control server access using hosts.allow and hosts.deny files

Answer : B

The user-specific crontab files are stored in the /var/spool/cron/crontabs directory, where each file is named after the username of the owner. These files are not meant to be edited directly, but rather through the crontab command. The other options are either incorrect or non-existent locations for user crontab files.Reference:

Where is the user crontab stored?

crontab running as a specific user

Location of the crontab file

Where is the User Crontab Stored?

Answer : A

With IPv6, the interface identifier of an unicast address is typically a 64-bit value that is used to identify a host's network interface. The interface identifier can be derived from the MAC address of the network card, or it can be randomly generated or manually configured. The interface identifier is the rightmost 64 bits of the most commonly encountered address types, such as global unicast (2000::/3) and link-local (fe80::/10). The interface identifier is different from the network prefix, which is the leftmost bits of the address that indicate the network or subnet to which the host belongs. The network prefix can vary in length, depending on the address type and the subnetting scheme. The network prefix and the interface identifier are separated by a double colon (::) in the IPv6 address notation. For example, in the address 2001:db8:1234:5678:abcd:ef12:3456:7890, the network prefix is 2001:db8:1234:5678 and the interface identifier is abcd:ef12:3456:7890.Reference: https://study-ccna.com/ipv6-interface-identifier/

https://networklessons.com/ipv6/ipv6-eui-64-explained

Answer : B

The lsof command stands forlist open files, and it can be used to show which processes have opened files on a device or mount point. This can help to identify which process is causing a device to be busy and prevent it from being unmounted. The syntax of the lsof command is:

lsof [options] [file|directory|device]

For example, to list the processes that have opened files on the /dev/sda1 device, the command would be:

lsof /dev/sda1

The output of the lsof command will show the process ID (PID), the user name, the command name, the file descriptor, the file type, the device number, the file size, the node number, and the file name for each open file. The file descriptor column can indicate the mode of access, such as r for read, w for write, u for read and write, and - for unknown.

The other options in the question are not relevant for this task. The debug command is used to examine and modify the memory of a running process. The nessus command is used to launch the Nessus vulnerability scanner. The strace command is used to trace system calls and signals of a process. The traceroute command is used to display the route and measure the transit delays of packets across a network.

LPI 102-500 Exam Objectives, Topic 104.3: Manage file permissions and ownership

LPI 102-500 Study Guide, Chapter 4: Devices, Linux Filesystems, Filesystem Hierarchy Standard, Section 4.3: Mounting and Unmounting Filesystems

lsof man page