Training course

This is a free, self-paced reading course for CompTIA Network+ (N10-009), the vendor-neutral benchmark for networking fundamentals, and the credential that proves you can design, configure, operate, and troubleshoot real networks rather than recite acronyms. It is written to be read straight through, in order, before you start drilling practice questions, so that a missed item becomes a gap you can name rather than a port number you half-remember.

The course is organized as one module per official exam domain, in the order CompTIA publishes them, and each module carries the domain’s published weight. On this exam that weighting says something specific: Networking Concepts and Network Troubleshooting together account for nearly half of N10-009, and they account for nearly half of this course. CompTIA is telling you it cares about strong fundamentals and methodical diagnosis more than breadth. The V9 outline also reflects how networks are actually built now (cloud-connected, software-defined, and wireless-first) so SD-WAN, VXLAN, zero trust, SASE/SSE, IPv6, and modern Wi-Fi sit alongside the durable core of subnetting, routing, and switching.

N10-009 (V9) Foundational level 5 modules Domain-weighted Self-paced Free account

What the course covers

Networking Concepts

Module 1 · 23%

The theory everything else stands on: the OSI model and encapsulation, networking appliances and what they do, cloud concepts and connectivity options, the ports-and-protocols table you have to know cold, transmission media and transceivers, topologies from three-tier to spine-and-leaf, IPv4 addressing and subnetting, and the modern-environment layer: SDN, SD-WAN, VXLAN, zero trust, SASE/SSE, and IPv6 addressing.

Network Implementation

Module 2 · 20%

Building networks that work: routing technologies including BGP, OSPF, route selection, NAT/PAT, and first-hop redundancy; switching with VLANs, 802.1Q trunking, link aggregation, and spanning tree; wireless design covering channels, AP deployment models, antennas, and authentication; and the physical layer of an installation, power, racks, cooling, MDF/IDF layout, and cable standards.

Network Operations

Module 3 · 19%

Running a network day to day: documentation and IPAM, lifecycle and change management, monitoring with SNMP, flow data, packet capture, and baselines, disaster recovery concepts including RPO/RTO and site strategies, the network services layer of DHCP, DNS, including DoH/DoT and DNSSEC, and NTP, and access methods from VPNs to jump boxes and out-of-band management.

Network Security

Module 4 · 14%

The security fundamentals every network professional owns: segmentation, IAM, AAA protocols, and zero-trust thinking; the attack landscape from VLAN hopping and MAC flooding to rogue DHCP, evil twins, and on-path attacks; and the defenses that counter them, device hardening, 802.1X, dynamic ARP inspection, DHCP snooping, ACLs, and security zones.

Network Troubleshooting

Module 5 · 24%

The heaviest domain on the exam. CompTIA’s structured troubleshooting methodology; cabling and physical-layer faults from duplex mismatches to fiber bend loss and PoE budgets; service issues spanning STP loops, VLAN misassignments, DHCP exhaustion, and DNS failures; performance problems like congestion, jitter, and wireless interference; and fluency with the full toolbox, ping, traceroute, dig, iperf, packet capture, toner probes, and discovery protocols.

How to use it

Read a module, then test that domain immediately rather than waiting until you have covered everything. The free Network+ sample questions are the quickest way to check whether a module landed, and the full-length blueprint-weighted exam sits on the N10-009 certification guide alongside the exam logistics, question count, timing, and the 720-on-900 scaled cut score. Reading the course itself requires a free Certifym account.

Two things repay work outside the reading. Subnetting has to become arithmetic you do without thinking, because under a 90-minute clock a slow calculation is a wrong answer; drill it until it is boring. And the performance-based questions put you into a simulated task rather than a list of options, which rewards having actually configured a VLAN, a trunk port, or a DHCP scope. A lab of virtual switches, or a home router you are willing to misconfigure, is worth more here than another pass through the notes.

CompTIA Network+ Training

A complete, self-paced Network+ (N10-009) course covering all five CompTIA objective domains: networking concepts, network implementation, network operations, network security, and network troubleshooting. Fifty-one lessons written to the level a working network technician actually needs — cabling and Ethernet, IPv4 and IPv6 addressing, dynamic routing, wireless (Wi-Fi 6/6E and 802.11ax fundamentals), WAN technologies, cloud networking, security controls, and a rigorous troubleshooting toolkit from cable testers through packet captures. Bundles with the 900+ Network+ practice questions to give both the depth and the recall practice needed to pass on the first attempt.

Module 1: Networking Concepts

Foundational vocabulary of networking — OSI and TCP/IP models, ports and protocols, topologies, IPv4 and IPv6 addressing, core services (DHCP, DNS, NTP), cloud concepts, and modern architectures like SDN, SD-WAN, SASE, and zero trust.

1 What Network+ Is 8 min Free preview
2 The OSI Model — Seven Layers 12 min 🔒
3 TCP/IP Model and Encapsulation 9 min 🔒
4 Ports and Protocols 12 min 🔒
5 Network Topologies and Types 8 min 🔒
6 IPv4 Addressing and Subnetting 15 min 🔒
7 IPv6 Addressing 10 min 🔒
8 Core Network Services — DHCP, DNS, NTP 12 min 🔒
9 Cloud Concepts and Deployment Models 10 min 🔒
10 Modern Network Architectures — SDN, SD-WAN, SASE, Zero Trust, IaC 10 min 🔒
11 Network Devices and Their OSI Layers 8 min 🔒

Module 2: Network Implementation

Building networks — routing protocols (OSPF, BGP, EIGRP), switching (VLANs, trunks, STP), wireless (802.11 standards, security, design), and the physical layer (copper, fiber, transceivers, installation).

1 Routing Technologies 12 min 🔒
2 Switching Technologies — VLANs, Trunks, STP 12 min 🔒
3 Wireless Standards — 802.11 Family 10 min 🔒
4 Wireless Design and Deployment 10 min 🔒
5 Wireless Security — WPA2, WPA3, and Enterprise Authentication 10 min 🔒
6 Copper Cabling — Categories, Standards, Terminations 8 min 🔒
7 Fiber Cabling — Single-Mode, Multi-Mode, Connectors 8 min 🔒
8 Transceivers, Media Converters, and Physical Interfaces 6 min 🔒
9 Physical Installation Best Practices 6 min 🔒
10 Implementation Planning — Change, Rollback, and Migration 6 min 🔒

Module 3: Network Operations

Running networks over time — documentation and IPAM, change and configuration management, monitoring (SNMP, syslog, flow data), performance metrics, disaster recovery, high availability, backup, and lifecycle management.

1 Documentation and Diagrams 8 min 🔒
2 IP Address Management in Practice 6 min 🔒
3 Configuration Management and Version Control 6 min 🔒
4 Monitoring — SNMP, Syslog, and Flow Data 10 min 🔒
5 Performance Metrics — Bandwidth, Latency, Jitter, Loss 8 min 🔒
6 Disaster Recovery — RTO, RPO, MTTR, MTBF 6 min 🔒
7 High Availability — Redundancy, Load Balancing, FHRP 10 min 🔒
8 Backup Strategies — Types, Rotation, and Testing 6 min 🔒
9 Network Hardening Baselines 6 min 🔒
10 Lifecycle Management — EOL, Patching, and Refresh 6 min 🔒

Module 4: Network Security

Securing networks — foundational security concepts, common attacks (Layer 2 and above), network access control, firewalls and IDS/IPS, secure remote access, and physical security.

1 Security Concepts — CIA, AAA, Defense in Depth 8 min 🔒
2 Common Attacks at Layer 2 8 min 🔒
3 Common Attacks Above Layer 2 10 min 🔒
4 Network Access Control — 802.1X, NAC, MAB 8 min 🔒
5 Firewalls, IDS, and IPS 10 min 🔒
6 Secure Remote Access — VPNs, Jump Boxes, and ZTNA 10 min 🔒
7 Physical Security 6 min 🔒
8 Wireless Security Deep Dive 8 min 🔒

Module 5: Network Troubleshooting

The largest exam domain — the CompTIA troubleshooting methodology, cable and interface issues, hardware and software diagnostic tools, and common problems at every layer from cable to routing to name resolution.

1 The CompTIA Troubleshooting Methodology 8 min 🔒
2 Cable Issues — Damage, Attenuation, EMI, Split Pairs 8 min 🔒
3 Cable Testing Tools 6 min 🔒
4 Interface Issues — Counters, Errors, and What They Mean 6 min 🔒
5 Hardware Tools for the Field 5 min 🔒
6 Command-Line Tools — Windows 8 min 🔒
7 Command-Line Tools — Linux 9 min 🔒
8 Software Tools — Wireshark, Nmap, and the Rest 8 min 🔒
9 Wireless Troubleshooting — Coverage, Roaming, and Interference 8 min 🔒
10 Common Issues — Layer 2 7 min 🔒
11 Common Issues — Layer 3 7 min 🔒
12 Common Issues — Services (DHCP, DNS, NAT, Certificates) 7 min 🔒

Frequently asked questions about the Network+ training course

Is the Network+ training course free?

Yes. The course costs nothing to read; it is behind a free Certifym account, with no payment and no card. It is funded by the same practice-exam catalog it sits alongside.

How is the course structured?

One module per official N10-009 exam domain, in CompTIA’s published order, with each module weighted to the domain’s published percentage: 23%, 20%, 19%, 14%, and 24%. Within each module the material is broken into short lessons, followed by key terms and further reading.

Does this replace CompTIA’s official training?

No. CompTIA publishes the authoritative N10-009 objectives document along with its own CertMaster courseware, and those are the reference of record. This course is an independent study companion, written to be read quickly and to slot alongside practice questions.

Do I need A+ before starting?

There is no enforced prerequisite. A+ is the step most technicians take before Network+, and it covers the hardware and operating-system ground this course does not, but plenty of candidates come straight to Network+ from a help desk role. What the course does assume is that you are willing to work at subnetting until it is automatic.

What should I do after finishing the course?

Move to blueprint-weighted practice questions and keep going until you are clearing the bar consistently in all five domains. Watch Network Security in particular: at 14% it is the lightest domain, which makes it the easiest to skip and the easiest to be quietly weak in. After the exam, Security+ is the usual next step, it assumes the networking foundation this course builds.

Is the course current with the latest Network+ version?

It is built against N10-009, which launched on June 20, 2024 and is the current Network+ exam. CompTIA typically retires a version about three years after release and overlaps it with its successor, so a V10 announcement is plausible on that horizon. Always confirm the active exam version at comptia.org before scheduling.

Trademark notice & independence. Certifym.net is operated by Certifym Exam Services, LLC and is not affiliated with, endorsed by, or sponsored by CompTIA, Inc. CompTIA® and Network+® are registered trademarks of CompTIA, Inc. Use of these marks is solely to identify the certification for which these study materials are intended. The N10-009 exam objectives, including the domain titles and weightings referenced above, are the property of CompTIA, Inc.; candidates should download the complete, official objectives directly from CompTIA at comptia.org.

All course content, questions, answers, and explanations on Certifym are original content created for study purposes. They are not actual CompTIA training materials or examination questions and are not represented as such. Studying with these materials does not guarantee a passing result on any live certification exam. Exam requirements, format, domain weights, pricing, and renewal policies are set by CompTIA and may change; always verify current details on the CompTIA site before scheduling your exam.