Free Practice Questions for CompTIA XK0-005 Exam

Running a command with & at the end sends it to the background, allowing the administrator to continue using the terminal for other tasks while the script runs. This is useful for long-running scripts that do not require immediate attention but need to keep running.

The ssh -X option enables X11 forwarding, which allows the user to run graphical applications on the remote server and display them on the local workstation. The user needs to specify the username, the server address, and the application name after the ssh -X command. The remote server also needs to have X11Forwarding enabled and xauth installed for this to work.

Setting vm.nr_hugepage in /etc/sysctl.conf ensures the setting is persisted across reboots.

Incorrect Options:

A: -a displays all; does not set.

B: Typo in variable name (hiigepage).

C: modprobe.conf is for module parameters, not sysctl variables.

The best tool to use when uploading the public key to the remote servers is B. ssh-copy-id. This tool will copy the public key from the local computer to the remote server and append it to the authorized_keys file, which is used for public key authentication. This tool will also create the necessary directories and files on the remote server if they do not exist. The other tools are either not suitable or not relevant for this task. For example:

A. scp is a tool for securely copying files between hosts, but it does not automatically add the public key to the authorized_keys file.

C. ssh-agent is a tool for managing private keys and passphrases, but it does not upload the public key to the remote server.

D. ssh-keyscan is a tool for collecting public keys from remote hosts, but it does not upload the public key to the remote server.

Comprehensive and Detailed Step-by-Step Explanation:

When making changes to systemd configuration files (such as unit files), the systemctl daemon-reload command must be run to reload the systemd manager configuration.

systemctl enable only enables a service to start at boot but does not apply configuration changes immediately.

systemctl restart restarts a specific service but does not reload the systemd daemon itself.

The missing option appears to be an unrelated or incorrect command.

The git fetch command downloads commits, files, and refs from a remote repository into the local one. It also updates the remote-tracking branches, which are references to the state of the remote branches. By running git fetch, the administrator can see the new branch created by the development team and then use git checkout to switch to it12.

In Git, if a branch does not exist and you need to create and switch to it in one command, use:

git checkout -b

OR

git switch -c

(For newer Git versions, switch is preferred.)

git checkout -b staging

-b creates a new branch.

staging is the new branch name.

This also switches to the new branch immediately.

Why the other options are incorrect?

A. git branch -m st → Incorrect, -m is used for renaming a branch, not creating one.

B. git commit -m staging → Incorrect, commit -m is used to commit changes with a message, not to create a branch.

C. git status -b staging → Incorrect, git status shows the current repository state, but -b is not a valid option for it.

These commands can display all the firewall rules applied to the Linux servers, depending on which firewall service is being used.

The firewall-cmd command is a utility for managing firewalld, which is a dynamic firewall service that supports zones and services. The --list-all option will show all the settings and rules for the default zone, or for a specific zone if specified. For example, firewall-cmd --list-all --zone=public will show the rules for the public zone1.

The ufw command is a frontend for iptables, which is a low-level tool for manipulating netfilter, the Linux kernel’s packet filtering framework. The status option will show the status of ufw and the active rules, or the numbered rules if verbose is specified. For example, ufw status verbose will show the numbered rules and other information2.

The other options are incorrect because:

A. ufw limit

This command will limit the connection attempts to a service or port using iptables’ recent module. It does not display any firewall rules2.

B. iptables -F

This command will flush (delete) all the rules in the selected chain, or all chains if none is given. It does not display any firewall rules3.

C. systemctl status firewalld

This command will show the status of the firewalld service, including whether it is active or not, but it does not show the firewall rules4.

F. iptables -A

This command will append one or more rules to the end of the selected chain. It does not display any firewall rules3.

The error "cannot resolve host" indicates a DNS resolution failure. The file /etc/resolv.conf defines the DNS server(s) to be used for name resolution.

/etc/interfaces configures network interfaces.

/etc/hosts.allow is for TCP wrappers access control, not DNS.

/etc/hostname defines the local system's hostname, not DNS configuration.

The docker build command is used to build an image from a Dockerfile and a context1. The Dockerfile is a text file that contains the instructions for creating the image, and the context is a set of files that can be used in the image creation process1. The file that the developer received is an example of a Dockerfile.

The -t option is used to specify a name and an optional tag for the image1. The name and tag are separated by a colon (:), and the tag is usually used to indicate the version of the image2. For example, -t myimage:1.0 means that the image will be named myimage and tagged as 1.0.

The last argument of the docker build command is the path to the context, which can be a local directory or a URL1. The dot (.) means that the current working directory is the context2. Therefore, docker build -t myimage:1.0 . means that the image will be built from the Dockerfile and the files in the current working directory, and it will be named myimage and tagged as 1.0.