Home - Test Your Linux Skills

{jssocials}

1. On which port does the ping command operate for Internet Control Message Protocol (ICMP) echo requests?

53
1337
33433
No port is used for ICMP.

2. Which of the following commands shows various statistics for a network interface such as packets and bytes received and transmitted along with errors and other such conditions?

ifconfig
ifstat
if -s
ifcond

3. Which of the following configuration lines in /etc/hosts.deny creates a deny-by-default policy where clients will need to be specifically allowed in /etc/hosts.allow?

* *
All: *
ALL: ALL
LOC: ALL

4. Which option to the ip command displays DNS names rather than merely IP addresses?

-n
-f
-r
-a

5. Which option to date changes the output to Coordinated Universal Time (UTC) regardless of the current time zone?

-u
-t
-s
-v

2. Which options to du will print a summary of information in a human-readable format?

-sh
-h
-s
-su

3. When running the lsblk command, there is no separate partition listed for /boot. From which partition is the system likely booted?

There is a /boot directory under the / partition.
The /boot partition is hidden.
The system has not yet built the /boot partition.
The /boot partition does not show up with lsblk.

4. When using systemcti to kill a process, what is the default signal sent to a process?

SIGKILL
SIGTERM
SIGINT
SIGCALL

5. When running fsck on an EXT3 filesystem, which option to fsck causes the operation to prompt when attempting a repair action?

-y
-f
-a
No option required

1. You are defining a service in /etc/xinetd.conf. Which option is used to configure the times that access to the service is allowed?

time_allowed
access_times
timed_access
access_when

2. Which of the following best describes the method to use with ssh in order to execute a single command on a remote server?

Use the -e option followed by the command.
Send the command after the other options as part of the command line.
Use the -execute option followed by the command.
Use the -s option followed by the command.

3. Which of the following commands generates an RSA key for use with ssh?

ssh -key rsa
ssh -gen-key rsa
ssh-keygen -t rsa
ssh-keygen rsa

4. When you’re using ssh-agent, which command and option lists the currently loaded keys?

ssh-agent -l
ssh -l
ssh-list-keys
ssh-add -l

5. Which of the following commands searches the entire filesystem for files with the setuid bit set?

find ./ -perm suid
find / -perm 4000
find / -type suid
find / -type f -perm setuid

2. Which of the following netmasks is used for a subnet described with a /25 in CIDR notation?

255.255.255.0
255.255.0.0
255.255.255.192
255.255.255.128

3. Which option to the traceroute command will use TCP SYN packets for the path trace?

-T
-t
-s
-i

4. Which of the following commands displays information about addresses, specifically only IPv6 addresses, currently in use on the computer?

ip addr
ip -6 addr
ip6add
ipv6addr

5. When examining open ports on the server, you see that TCP port 3000 is listed with no corresponding protocol name, such as SMTP, IMAP over SSL (IMAPS), and so on. In which file would you find a list of port-to-protocol translations that could be customized to add this new port?

/etc/ports
/etc/p2p
/etc/ppp
/etc/services

1. You are working with journalctl and need to see only messages that are at a debug priority. Which of the following options enables this scenario?

-pri debug
-prior debug
-d debug
-p debug

2. Which of the following commands views the contents of a message that exists in the Postfix queue?

postshow
postless
postmore
postcat

3. You are deploying an Exim server and need to work with the firewall to ensure the proper incoming ports are open. Which protocol and port should you allow inbound for normal Simple Mail Transfer Protocol (SMTP) traffic?

TCP/23
TCP/25
TCP/110
TCP/143

4. Which of the following commands places a file into the print queue?

5. Which function of the hwclock command will set the hardware clock to the current system time?

-w
-s
-a
-m

LPI 101 and 102 Free Practice Test 2026

Linux quiz