A junior administrator is trying to set up a passwordless SSH connection to one of the servers. The administrator follows the instructions and puts the key in the authorized_key file at the server, but the administrator is still asked to provide a password during the connection.
Given the following output:
Which of the following commands would resolve the issue and allow an SSH connection to
be established without a password?
Correct Answer:
B
The command mv .ssh/authorized_key .ssh/authorized_keys will resolve the issue and allow an SSH connection to be established without a password. The issue is caused by the incorrect file name of the authorized key file on the server. The file should be named authorized_keys, not authorized_key. The mv command will rename the file and fix the issue. The other options are incorrect because they either do not affect the file name (restorecon or chmod) or do not restart the SSH service (systemct1). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 410.
A Linux systems administrator needs to copy files and directories from Server A to Server
Correct Answer:
CE
The rsync and scp commands can be used to copy files and directories from Server A to Server B. Both commands can use SSH as a secure protocol to transfer data over the network. The rsync command can synchronize files and directories between two locations, using various options to control the copying behavior. The scp command can copy files and directories between two hosts, using similar syntax as cp. The rsyslog command is used to manage system logging, not file copying. The cp command is used to copy files and directories within a single host, not between two hosts. The reposync command is used to synchronize a remote yum repository to a local directory, not copy files and directories between two hosts. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Networking Fundamentals, pages 440-441.
Users are unable to create new files on the company's FTP server, and an administrator is troubleshooting the issue. The administrator runs the following commands:
Which of the following is the cause of the issue based on the output above?
Correct Answer:
C
The cause of the issue based on the output above is C. The inodes is at full capacity and would affect file creation for users.
An inode is a data structure that stores information about a file or directory, such as its name, size, permissions, owner, timestamps, and location on the disk. Each file or directory has a unique inode number that identifies it. The number of inodes on a filesystem is fixed when the filesystem is created, and it determines how many files and directories can be created on that filesystem. If the inodes are exhausted, no new files or directories can be created, even if there is enough disk space available.
The output for the second command shows that the /ftpusers/ filesystem has 0% of inodes available, which means that all the inodes have been used up. This would prevent users from creating new files on the FTP server. The administrator should either delete some unused files or directories to free up some inodes, or resize the filesystem to increase the number of inodes.
The other options are incorrect because:
* A. The users do not have the correct permissions to create files on the FTP server.
This is not true, because the output for the first command shows that the /ftpusers/ filesystem has 26% of disk space available, which means that there is enough space for users to create files. The permissions of the files and directories are not shown in the output, but they are not relevant to the issue of inode exhaustion.
* B. The ftpusers filesystem does not have enough space.
This is not true, because the output for the first command shows that the /ftpusers/ filesystem has 26% of disk space available, which means that there is enough space for users to create files. The issue is not related to disk space, but to inode capacity.
* D. ftpusers is mounted as read only.
This is not true, because the output for the first command does not show any indication that the /ftpusers/ filesystem is mounted as read only. If it was, it would have an (ro) flag next to the mounted on column. A read only filesystem would prevent users from creating or modifying files on the FTP server, but it would not affect the inode usage.
Joe, a user, is unable to log in to the Linux system Given the following output:
Which of the following command would resolve the issue?
Correct Answer:
B
Based on the output of the image sent by the user, Joe is unable to log in to the Linux system because his account has been locked due to too many failed login attempts. The pam_tally2 -u joe -r command will resolve this issue by resetting Joe’s failed login counter to zero and unlocking his account. This command uses the pam_tally2 module to manage user account locking based on login failures. The usermod -s /bin/bash joe command will change Joe’s login shell to /bin/bash, but this will not unlock his account. The passwd -u joe command will unlock Joe’s password if it has been locked by passwd -l joe, but this will not reset his failed login counter or unlock his account if it has been locked by pam_tally2. The chage -E 90 joe command will set Joe’s account expiration date to 90 days from today, but this will not unlock his account or reset his failed login counter. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Securing Linux Systems, page 537.
An administrator recently updated the BIND software package and would like to review the default configuration that shipped with this version. Which of the following files should the administrator review?
Correct Answer:
A
After installing a new version of a package that includes a configuration file that already exists on the system, such as /etc/httpd/conf/httpd.conf, RPM will create a new file with the .rpmnew extension instead of overwriting the existing file. This allows the administrator to review the default configuration that shipped with this version and compare it with the current configuration before deciding whether to merge or replace the files. The /etc/named.conf.rpmsave file is created by RPM when a package is uninstalled and it contains a configuration file that was modified by the administrator. This allows the administrator to restore the configuration file if needed. The /etc/named.conf file is the main configuration file for the BIND name server, not the httpd web server. The /etc/bind/bind.conf file does not exist by default in Linux systems. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Packages and Software, page 561.
