Free Linux Foundation LFCS Exam Questions

Become Linux Foundation Certified with updated LFCS exam questions and correct answers

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Total 260 Questions | Updated On: Apr 03, 2026

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Question 1

What is a purpose of an SSH host key?

A : It must be sent by any SSH client in addition to a user key in order to identify the client's host.

B : It provides the server-s identity information to connecting SSH clients.

C : It is the root key by which all user SSH keys must be signed.

D : It authenticates any user that logs into a remote machine from the key-s host.

E : It is used by system services like cron, syslog or a backup job to automatically connectto remote hosts.

Answer: B

Question 2

When running the commandsed -e "s/a/b/" /tmp/file >/tmp/fileWhile /tmp/file contains data, why is /tmp/file empty afterwards?

A : The file order is incorrect. The destination file must be mentioned before the command to ensure redirection.

B : The command sed did not match anything in that file therefore the output is empty.

C : When the shell establishes the redirection it overwrites the target file before the redirected command starts and opens it for reading.

D : Redirection for shell commands do not work using the > character. It only works using the | character instead.

Answer: C

Question 3

How can the normal output of a command be written to a file while discarding the error output?

A : command >2>file 1&>/dev/null

B : command < output > /dev/null

C : command > discard-error > file

D : command > /dev/null 2&>1 output

E : command >file 2>/dev/null

Answer: A

Question 4

How is a display manager started?

A : It is started by a user using the command startx.

B : It is started like any other system service by the init system.

C : It is started by inetd when a remote hosts connects to the X11 port.

D : It is started automatically when a X11 user logs in to the system console.

Answer: B

Question 5

What is true regarding TCP port 23?

A : Port 23 is the well known port for the telnet service which is a plain text protocol that should no longer be used.

B : Port 23 is the well known port for the SSH service which provides secure logins.

C : Port 23 is the well known port for the rlogin service which is SSL secured by default.

D : Port 23 is the well known port for the system login services which are encrypted when the user runs the starttls command in his login shell.

Answer: A

Page: 1 / 52

Total 260 Questions | Updated On: Apr 03, 2026

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