CompTIA CompTIA Linux+ LX0-104 Questions & Answers

• Question 1:

  Which configuration file does sudo read when determining if a user is permitted to run applications with root privileges?

  A. /etc/security.conf

  B. /etc/supasswd

  C. /etc/sudoers

  D. /etc/sudo.conf

  Correct Answer: C

• Question 2:

  How do shadow passwords improve the password security in comparison to standard passwd passwords?

  A. Shadow passwords are stored in plain text and can be checked for weak passwords.

  B. Every shadow password is valid for 45 days and must be changed afterwards.

  C. The system's host key is used to strongly encrypt all shadow passwords.

  D. Shadow passwords are always combined with a public key that has to match the user's private key.

  E. Regular users do not have access to the password hashes of shadow passwords.

  Correct Answer: E

• Question 3:

  Which of the following commands can modify or set the password expiration for a user? (Choose two correct answers.)

  A. chage

  B. chexpiration

  C. shadowconfig

  D. passwd

  E. userconf

  Correct Answer: AD

• Question 4:

  What happens if the password of a user in the /etc/shadow file is prepended with the ! character?

  A. When logging in, the user automatically gets root privileges in addition to his regular privileges.

  B. The password is inverted which allows the user to log in with any password other than the current password.

  C. The user is disabled and all login methods, including but not limited to password based logins, are disabled.

  D. Upon the next log in, the user is forced to change his password.

  E. The password becomes invalid which disables password based logins although other login methods remain usable.

  Correct Answer: E

• Question 5:

  Which of the following resources can be directly limited for a given user using ulimit? (Choose three correct answers.)

  A. Maximum seconds of CPU time spent.

  B. Maximum number of open file descriptors.

  C. Maximum number of processes available.

  D. Maximum number of concurrent login sessions.

  E. Maximum seconds of login duration per session.

  Correct Answer: ABC

• Question 6:

  Which of the following commands gets the GnuPG public key with the id 63B4835B from the keyserver example.com?

  A. gpg

  Correct Answer: A

• Question 7:

  Which command is used to add OpenSSH private keys to a running ssh-agent instance? (Specify the file name only without any path.)

  A. ssh-add

  Correct Answer: A

• Question 8:

  What is true regarding public and private SSH keys? (Choose two correct answers.)

  A. Several different public keys may be generated for the same private key.

  B. The private key must never be revealed to anyone.

  C. For each user account, there is exactly one key pair that can be used to log into that account.

  D. To maintain the private key's confidentiality, the SSH key pair must be created by its owner.

  E. To allow remote logins, the user's private key must be copied to the remote server.

  Correct Answer: BD

• Question 9:

  Which of the following commands can be used to limit the amount of memory a user may use?

  A. umask

  B. usermod

  C. ulimit

  D. passwd

  E. chage

  Correct Answer: C

• Question 10:

  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.)

  A. /etc/shadow

  Correct Answer: A