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LPIC-3 Certification Guide: Mixed Environments, Security, and High Availability

Mon Jul 13 2026 00:00:00 GMT+0000 (Coordinated Universal Time)~7 min read

The LPIC-3 certification is the highest level of the Linux Professional Institute (LPI) certification program. It validates senior-level Linux administration skills across multiple specializations, including mixed network environments with Unix and Windows integration, enterprise security hardening, and high-availability infrastructure.

Candidates must hold an active LPIC-2 certification before attempting any LPIC-3 exam.

Exam Overview

LPIC-3 offers three specialization exams. Passing any one of them earns the LPIC-3 certification:

| Exam | Code | Duration | Questions | Passing Score | | ---------------------------------- | ---- | ---------- | --------- | ------------- | | Mixed Environment | 300 | 90 minutes | 60 | 500 / 800 | | Security | 303 | 90 minutes | 60 | 500 / 800 | | Virtualization & High Availability | 304 | 90 minutes | 60 | 500 / 800 |

All exam objectives are updated approximately every five years. The current objectives (version 3.0 for 300, version 2.0 for 303/304) were released in 2023.

Exam 300: Mixed Environment

The Mixed Environment exam covers integration of Linux systems with Unix, Windows, and macOS networks. It focuses on identity management, file sharing, and directory services.

Topics and Weighting

| Topic | Weight | Description | | --------------------------------- | ------ | -------------------------------------------------------------------------------------------------------- | | Samba Basics | 5% | NetBIOS/NetBEUI concepts, Samba daemons (smbd, nmbd, winbindd), smb.conf configuration | | Samba File Sharing | 10% | Share definitions, file permissions, browse lists, printer sharing | | Samba Authentication and Security | 15% | User-level and share-level security, domain membership, SID mapping, idmap backends | | Samba Identity Management | 10% | winbind integration, PAM configuration, name service switch (nsswitch) | | LDAP Integration | 20% | OpenLDAP server setup, LDAP schema, search filters, TLS encryption, LDAP authentication with PAM and NSS | | Kerberos Authentication | 15% | Kerberos realm configuration, keytab management, ticket policies, integration with Samba and LDAP | | Name Services | 10% | BIND DNS configuration, zone files, dynamic DNS updates with Samba AD | | File and Print Services | 10% | CUPS integration, printer sharing via Samba, access control | | NFS and Network File Systems | 5% | NFSv4 exports, Kerberized NFS, automounter |

Key Skills

  • Configure Samba as a standalone server and as a domain member
  • Set up and manage an OpenLDAP directory service
  • Integrate Linux clients into Active Directory domains using SSSD and winbind
  • Configure Kerberos authentication across mixed environments
  • Manage SID mapping with autorid, rid, and ad backends

Exam 303: Security

The Security exam covers enterprise Linux security hardening, from system-level controls to cryptographic infrastructure and mandatory access control systems.

Topics and Weighting

| Topic | Weight | Description | | -------------------------------------- | ------ | ---------------------------------------------------------------------------------------------------------- | | Cryptography | 15% | Symmetric and asymmetric encryption, OpenSSL, GPG, PKI infrastructure, certificate management | | System Security | 15% | Pluggable Authentication Modules (PAM), secure console configuration, user resource limits, login policies | | Network Security | 15% | Packet filtering with nftables/iptables, firewalld, fail2ban, TCP wrappers | | Mandatory Access Control | 20% | SELinux and AppArmor: policies, contexts, booleans, audit logs, troubleshooting | | Event Monitoring and Logging | 10% | rsyslog, systemd-journald, auditd, log rotation, remote logging | | File Integrity and Intrusion Detection | 10% | AIDE, Tripwire, rkhunter, chkrootkit, file integrity verification | | Vulnerability Assessment | 10% | OpenVAS, Lynis, security scanning, patch management, CVE tracking | | Incident Response | 5% | Evidence collection, forensic imaging, chain of custody, incident containment |

Key Skills

  • Create and manage GPG keys, certificates, and Certificate Authorities
  • Configure SELinux policies and troubleshoot denials using audit logs and sealert
  • Implement host-based firewalls with nftables (modern syntax, sets, maps, chains)
  • Deploy file integrity monitoring with AIDE across server fleets
  • Set up centralized logging and audit monitoring with rsyslog and auditd

Exam 304: Virtualization and High Availability

The Virtualization and High Availability exam covers virtual machine management, container orchestration, and enterprise cluster configuration.

Topics and Weighting

| Topic | Weight | Description | | -------------------------- | ------ | ------------------------------------------------------------------------------- | | Virtual Machine Management | 15% | KVM/QEMU configuration, libvirt, virsh, VM lifecycle, snapshots, live migration | | Container Management | 10% | Docker, Podman, container images, volumes, networking, Docker Compose | | Container Orchestration | 10% | Kubernetes concepts, pods, deployments, services, kubectl | | High Availability Concepts | 15% | Cluster architectures, quorum, fencing (STONITH), resource groups | | Cluster Management | 15% | Pacemaker/Corosync configuration, resource agents, constraints, colocation | | Cluster Storage | 15% | DRBD, shared storage (iSCSI, FC), GFS2, OCFS2 cluster filesystems | | Load Balancing | 10% | LVS (Linux Virtual Server), HAProxy, keepalived, VRRP | | Backup and Restore | 10% | Cluster-aware backup strategies, snapshots, disaster recovery planning |

Key Skills

  • Create and manage KVM virtual machines using virsh and virt-manager
  • Build and deploy containerized applications with Docker and Podman
  • Configure a Pacemaker/Corosync high-availability cluster with DRBD storage
  • Implement virtual IP failover with keepalived
  • Manage Kubernetes pods, deployments, and services for container orchestration

Study Recommendations

Prerequisites

LPIC-3 exams require a solid LPIC-2 foundation. Key prerequisites include:

  • Kernel management and modules (LPIC-2 201)
  • System startup and recovery (LPIC-2 201)
  • Advanced storage administration (LPIC-2 202)
  • Network configuration and services (LPIC-2 202)

Study Strategy

  1. Choose your specialization based on your current role. Security (303) is the most broadly applicable. Mixed Environment (300) is essential for enterprise directory integration roles. Virtualization & HA (304) is ideal for infrastructure/platform engineers.
  2. Practical lab work is essential. Set up VMs for each exam's core technologies: a Samba AD domain controller for 300, SELinux-enforcing servers for 303, a Pacemaker cluster with DRBD for 304.
  3. Review the official objectives from the LPI website. Pay close attention to the weight percentages — topics with higher weights deserve more study time.
  4. Practice with realistic questions. Work through our practice exam generator below to identify knowledge gaps and build exam confidence.

Recommended Resources

  • LPI Official: LPIC-3 300 Objectives
  • LPI Official: LPIC-3 303 Objectives
  • LPI Official: LPIC-3 304 Objectives
  • LPIC-3 300: Mixed Environment (B. Smith, No Starch Press)
  • Linux Security: SELinux, AppArmor, and Beyond (O'Reilly)
  • Pacemaker/Corosync Cluster from Scratch (ClusterLabs Documentation)
  • Red Hat Enterprise Linux 9 Security Hardening Guide

Practice Questions

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