Concepts·CompTIA Linux+

Linux+ XK0-006 domains and question style

XK0-006 is 90 questions in 90 minutes, scored on a 100-900 scale with 720 to pass, across five domains. This guide covers what that structure means for how you prepare - one minute a question, no domain small enough to skip, and a scaled score nobody can convert back to a raw one - and introduces the two machines every later page runs on.

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PlatformsUbuntu 26.04 LTS + AlmaLinux 10.2
Mandatory access controlAppArmor on Ubuntu, SELinux enforcing on Alma
Firewallufw / nftables 1.1.6
TimeAbout 11 min

Exam structure and domain names are CompTIA's published objectives for XK0-006, linked below. Nothing on this page is derived from this site's practice questions - a question bank is edited, and a guide that quotes one goes quietly out of date.

Both package families, because XK0-006 does not tell you which one you will get. The hostnames are provisioning artefacts shared with the other Linux paths; the OS column is what matters.
Server Name	IP Address	OS	Roles	CPU	RAM	HDD
LPLUS-A01	192.168.0.73	Ubuntu 26.04 LTS	Debian-family host - apt, ufw, netplan, AppArmor	2 Core	4 GB	50 GB
LPLUS-B01	192.168.0.74	AlmaLinux 10.2	RPM-family host - dnf, firewalld, NetworkManager, SELinux	2 Core	4 GB	50 GB

This guide includes

Use this before booking XK0-006. This matters because the exam is family-neutral - a question may name apt or dnf without warning, which is why the lab runs one machine of each.

reading the five domains, and what each is worth
seeing what that structure implies for how you revise
meeting the two machines, one from each package family

Before you start

The two machines this path uses
One of each package family, because the exam is family-neutral.
bash Example session
```
$. /etc/os-release; echo "$PRETTY_NAME"; uname -r; hostnamectl | head -3Ubuntu 26.04 LTS7.0.0-30-generic  Static hostname: lplus-a01        Icon name: computer-vm          Chassis: vm 🖴$. /etc/os-release; echo "$PRETTY_NAME"; uname -r; hostnamectl | head -3Ubuntu 26.04 LTS7.0.0-30-generic  Static hostname: lplus-a01        Icon name: computer-vm          Chassis: vm 🖴
```
Note
XK0-006 does not name a distribution. It examines Linux, so a path that only ever showed apt would have taught half of it. Every guide here whose commands differ between the families shows both, captured on both.

The hostnames are provisioning artefacts; the OS column is what matters.

AlmaLinux rather than RHEL. The RPM family is what is examined, not one vendor's build of it, and everything here behaves identically on Rocky and RHEL.

Expected resultUbuntu 26.04 LTS and AlmaLinux 10.2, on kernels 7.0.0-30-generic and 6.12.0-211.7.3.el10_2.

Success conditionYou know which machine each command on this path ran on.
The five domains, and what the structure implies
Read CompTIA's objectives, then plan around the clock rather than the weights.
bash Example session
```
$printf '%-14s %s\n' shell "$BASH_VERSION" pkg "$(command -v apt-get dpkg | tr '\n' ' ')" fw "$(command -v ufw | tr '\n' ' ')" mac "$(command -v aa-status apparmor_status 2>/dev/null | head -1)"shellpkg            /usr/bin/apt-get /usr/bin/dpkgfw             /usr/sbin/ufwmac            /usr/sbin/aa-status$printf '%-14s %s\n' shell "$BASH_VERSION" pkg "$(command -v dnf rpm | tr '\n' ' ')" fw "$(command -v firewall-cmd | tr '\n' ' ')" mac "$(command -v getenforce | tr '\n' ' ')"shellpkg            /usr/bin/dnf /usr/bin/rpmfw             /usr/bin/firewall-cmdmac            /usr/sbin/getenforce
```
Note
The five domains are System Management, Services and User Management, Security, Automation/Orchestration/Scripting, and Troubleshooting. CompTIA publishes the weighting on the objectives page linked below; it is worth reading once, and worth not memorising, because no domain is small enough to skip.

One minute per question is the number that should change your preparation. 90 questions in 90 minutes rewards recognising the right answer, not deriving it. That is a different skill from a performance exam like RHCSA or LFCS, where the end state is all that is graded.

720 of 900 is not 80%. The scale runs 100-900, not 0-900, and CompTIA does not publish the raw-to-scaled mapping. Anyone telling you exactly how many questions you may get wrong is guessing. Aim comfortably clear of the line rather than calculating it.

Troubleshooting is a domain here, not an afterthought. On most administrator exams it is implicit; XK0-006 examines it directly, which is why this path has diagnosis-first pages rather than a troubleshooting table bolted to the end of a configuration guide.

Expected resultTwo machines reporting different package tools and different firewalls - apt-get/dpkg with ufw against dnf/rpm with firewalld.

Success conditionYou can see why this exam needs two machines rather than one.

Troubleshooting

Practice questions do not look like the exam's domains.

Why: Two pools ship on this site: linux-plus-006.json is XK0-006 with five domains, and linux-plus.json is the retired four-domain exam.

Fix:Check the domain names before practising. Five domains including 'Services and User Management' is XK0-006; four with 'Scripting and Automation' as domain 2 is the old paper.
Revision covers one package family only.

Why: XK0-006 is family-neutral and a question may name apt or dnf, ufw or firewalld, without warning.

Fix:Work on one host of each family. Four things differ - package manager, firewall, mandatory access control and network configuration - and the rest transfers.
Trying to work out how many questions may be answered wrongly.

Why: The pass mark of 720 is on a 100-900 scaled range, and CompTIA does not publish the mapping from raw answers to scaled score.

Fix:Treat it as unanswerable and use per-domain accuracy instead. Aim comfortably above your practice threshold in every domain rather than counting a margin that cannot be derived.

Official sources

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