LFCS practice exam 2
A timed, hands-on practice exam.
Level 301 · 20 lessons · 18 practice labs
Lessons
Task sets
- Task set A: system administration: In the first part of the second practice exam, you solve system administration tasks under time pressure.
- Task set B: storage and networking: In the second part of the second practice exam, you solve and verify storage and networking tasks under time pressure.
- Task set C: services and security: In the last part of the second practice exam, you solve service and security tasks under time pressure.
- Short task: redo your hardest task set against the clock
Scenarios: services, repositories and network rules
- Scenario: scheduling a service health check with a systemd timer: You will write a check service and timer that run at regular intervals and see the output in the journal.
- Scenario: repairing a service that fails because of a wrong environment variable: You will find the environment setting in the service unit, fix it and verify the service starts correctly.
- Scenario: creating a local apt repository and installing from it: You will publish packages as a repository in a directory, register it in sources.list and install from it.
- Scenario: combining two network interfaces for redundancy: You will build a bond device and test that the connection survives when one interface drops.
- Scenario: saving iptables rules and restoring them after a reboot: You will export rules to a file and load them at boot, giving you a persistent packet-filtering policy.
- Scenario: redirecting a local port to another: You will redirect incoming connections to an internal service port with a NAT rule and test with curl.
- Short task: set up a redundant link and a persistent firewall together
Scenarios: storage, permissions and backup
- Scenario: diagnosing a listening-port conflict: You will find with ss which process holds a port and reconfigure the conflicting service.
- Scenario: growing an LVM volume and expanding its file system: You will add a disk to the volume group, grow the logical volume and expand the file system online.
- Scenario: setting up a memory-backed scratch workspace: You will mount a size-limited tmpfs and explain that it disappears on reboot and what it suits.
- Scenario: repairing and mounting a file system image: You will check a damaged image file with fsck and mount it through a loop device.
- Scenario: setting group access on a shared directory with ACLs: You will give chosen users special permissions on a directory with setfacl and verify with getfacl.
- Scenario: extracting failed logins and taking a verified backup: You will pull failed logins from the logs and store the evidence archive in a verifiable form with tar and sha256sum.
- Short task: make room for growing data and fix shared-folder access
Review and final
- Review and closing the gaps: You will review the mistakes and skipped tasks from the practice, identify the weak topics and draw up a plan to close them.
- Capstone: a timed 2-hour full mock exam
Practice labs
- Read when timers will next run: With systemctl list-timers you list active timers with last and next run times and find the one that has never run.
- Set up a timer for a weekly disk report: You write service and timer units that produce a disk-usage report every Monday morning and verify by triggering it manually.
- Catch up a job missed while powered off: You add Persistent and a randomised delay so a nightly job missed while the server was off runs at boot and prove it with a reboot.
- Find a service's environment variables: You show which environment file a running service reads and which variables are defined in its process.
- Change a service's port without touching the package file: In a drop-in created with systemctl edit you change the listening port and show the packaged unit file is unchanged.
- Find why a drop-in has no effect: You diagnose with systemd-delta and the journal a service failing because a drop-in did not reset ExecStart and fix it.
- List the interfaces attached to a bridge: On a virtualisation host you report the bridge device, its members and learned MAC addresses with bridge commands.
- Build a netplan bridge for virtual machines: You put the physical interface into a bridge with netplan, move the address to the bridge and verify a VM gets an address from the network.
- Separate two VLANs on a bridge: You split two VLANs arriving over one physical link into separate bridges and test that each VM reaches only its own network.
- Read an nftables ruleset: From nft list ruleset output you work out which ports are open and what the default policy is.
- Define allowed admin addresses as a set: You write an nftables rule allowing SSH only from an address set and add a new address to the set without rewriting the rule.
- Repair a rule file that doesn't load at boot: You check and fix an nftables.conf that fails to load at boot over a syntax error and prove with a reboot that the service is enabled.
- Read a file system's block and inode usage: With df and tune2fs you report a volume's fill level, inode usage and last check date.
- Check and shrink an unmounted volume: You unmount and check an over-allocated ext4 volume, shrink it safely together with its file system and verify the data.
- Recover a damaged superblock from its backup: On a disk image that won't mount you locate a backup superblock, repair with it and count the recovered files.
- Extract a single file from an archive: You list a compressed backup archive's contents and extract only the deleted configuration file with its original permissions.
- Mirror a project folder with excludes: You mirror Kozalak Mobilya's drawing folder to a second disk with rsync, excluding caches and temp files, and show the difference with a dry run.
- Set up daily incremental backups with hard links: You write a script producing space-saving daily copies with rsync --link-dest, run it for three days and restore a file as it was on day two.
About this course
A timed, hands-on practice exam.
What you will learn
- Task sets
- Scenarios: services, repositories and network rules
- Scenarios: storage, permissions and backup
- Review and final
Prerequisites
You should be comfortable with the level 101 and 201 topics of the same path.
Lab environment
Lessons run in your own Kali Linux terminal in the browser, connected to a private lab network. Nothing to install.
Frequently asked questions
- Is this course right for my level?
- The course is at level 301; it assumes you know the topics of the lower-level courses.
- Is there anything to install?
- No. Every lesson runs in your own lab environment that opens in the browser.
- How do lessons work?
- Each lesson has 8 to 10 steps and a short quiz. Early steps show the command to type, later steps give less help; if two attempts fail, the solution opens.
- Can I try it for free?
- Yes. The first three lessons of every course are free.