CompTIA Network+ N10-009

CompTIA Network+ Study Guide

Everything you need to pass the N10-009 — exam structure, domain breakdown, a realistic study plan, the highest-priority topics, and links to every Network+ concept covered on IT Study Hub.

N10-009
Exam code
90
Max questions
720/900
Passing score
90 min
Time limit

Who Should Take Network+

The CompTIA Network+ is the benchmark certification for anyone working in networking — IT support technicians who need to understand what's happening beyond the workstation, aspiring network administrators, and help desk staff who regularly deal with connectivity issues. It's the natural step after CompTIA A+ and a prerequisite mindset for Security+.

Network+ proves you understand how networks actually work — not just that you can configure a device, but why packets move the way they do, what happens when they don't, and how to fix it. The N10-009 version places heavy emphasis on troubleshooting (29% of the exam) and security in a networking context.

N10-009 vs N10-008 — What Changed

The N10-009 (current version) kept the same 5 domains as N10-008 but rebalanced the weightings. The biggest change: Networking Fundamentals dropped from 24% to 23% while Network Troubleshooting increased from 17% to 18%. Cloud and virtualisation content is more integrated throughout. If you're using study materials, make sure they target N10-009 specifically.

Exam Domain Weightings

1. Networking Fundamentals
23%
23%
2. Networking Implementations
21%
21%
3. Network Operations
19%
19%
4. Network Security
19%
19%
5. Network Troubleshooting
18%
18%

Study Resources by Domain

Domain 1
Networking Fundamentals
23%

The foundation — OSI model, TCP/IP, IP addressing, subnetting, protocols, wireless standards, and cable types. If you understand how a packet moves from source to destination, most of this domain makes sense. Subnetting is the single most important skill here.

OSI Model ExplainedAll 7 layers, protocols at each layer, PDU names, and layer identification TCP/IP Model4-layer model vs OSI, encapsulation, how packets flow TCP vs UDP3-way handshake, connection-oriented vs connectionless, use cases IP Address ClassesClass A/B/C ranges, private vs public, APIPA, loopback Subnetting GuideCIDR notation, subnet masks, calculating hosts per subnet Subnetting Deep Dive — Magic Number & VLSMFastest exam method, VLSM, worked examples, PBQ practice IPv4 vs IPv6Address format, types (unicast, multicast, anycast), dual-stack Ports & Protocols ReferenceEvery port tested on Network+ — FTP, SSH, DNS, HTTP, SMTP, RDP, SNMP DNS Record TypesA, AAAA, MX, CNAME, PTR, SOA, NS, TXT records explained Wireless Networking Explained802.11 standards, WPA2/WPA3, 802.1X, site surveys, antenna types MAC Addresses ExplainedLayer 2 addressing, ARP, MAC vs IP, OUI
Domain 2
Networking Implementations
21%

How you actually configure and deploy networks — VLANs, inter-VLAN routing, routing protocols, DHCP, NAT, and wireless deployment. Performance-based questions frequently show network diagrams and ask you to spot misconfigurations.

VLANs ExplainedAccess ports, trunk ports, 802.1Q tagging, inter-VLAN routing Network SegmentationVLANs, DMZ, microsegmentation, air gaps, jump servers Routing ProtocolsStatic vs dynamic, RIP, OSPF, BGP, EIGRP — when to use each Router vs SwitchLayer 2 vs Layer 3 devices, when each is used DHCP ExplainedDORA process, scopes, reservations, DHCP relay NAT ExplainedStatic NAT, PAT/NAT overload, private vs public IP translation DNS ExplainedRecursive vs iterative queries, zones, forwarders, caching Cloud Computing ConceptsIaaS/PaaS/SaaS, public/private/hybrid cloud, shared responsibility
Domain 3
Network Operations
19%

Monitoring, documentation, high availability, and remote access. Often underestimated — but 19% is ~17 questions. SNMP, syslog, VPN types, and high availability terms (HSRP, LACP) are the most consistently tested topics here.

VPNs ExplainedIPSec, SSL/TLS VPN, site-to-site vs remote access, split tunneling SNMP — Ports & ProtocolsSNMP v1/v2c/v3, UDP 161/162, traps vs polling Network Troubleshooting Commandsipconfig, ping, tracert, netstat, nslookup, arp Home Lab Setup GuidePractice network operations hands-on with VMs
Domain 4
Network Security
19%

Security from a network engineer's perspective — firewalls, IDS/IPS, wireless security, VPNs, authentication (RADIUS, 802.1X), and network attacks. This overlaps heavily with Security+ and gives you a head start if you plan to take both.

Firewall TypesPacket filtering, stateful, NGFW, WAF, ACLs Network AttacksDDoS, MITM, ARP poisoning, DNS spoofing, VLAN hopping Wireless Security ProtocolsWEP, WPA, WPA2, WPA3, 802.1X, RADIUS for enterprise Wi-Fi Network SegmentationDMZ, screened subnet, microsegmentation, zero trust networking Cryptography FundamentalsSymmetric vs asymmetric, hashing, TLS, certificates PKI & Digital CertificatesCA hierarchy, certificate types, HTTPS, certificate validation Zero Trust SecurityNever trust always verify, microsegmentation, ZTNA Identity & Access ManagementMFA, RADIUS, 802.1X, LDAP, Kerberos for network auth
Domain 5
Network Troubleshooting
18%

Scenario-based troubleshooting — given a symptom, identify the cause and the fix. This domain rewards candidates who have hands-on experience. Performance-based questions here often show a network topology and ask you to identify the fault.

Network Troubleshooting Commandsipconfig, ping, tracert, netstat, nslookup — with real output examples Ports & Protocols ReferenceKnow which port belongs to which service — essential for firewall/connectivity troubleshooting Subnet Masks ExplainedReading and troubleshooting subnet mask misconfigurations Default Gateway ExplainedWhat it does, misconfiguration symptoms, troubleshooting steps

Realistic Study Plan — 8 Weeks

Most candidates need 6–10 weeks to prepare for Network+, depending on their background. This plan assumes 1–2 hours of study per day.

Week 1
OSI, TCP/IP, IP Addressing
OSI model (all 7 layers cold) · TCP vs UDP · IPv4 classes · private vs public IP ranges · APIPA · loopback · ports reference
Week 2
Subnetting
CIDR notation · subnet masks · calculating usable hosts · subnetting practice problems daily until fast · IPv6 address types
Week 3
Switching & VLANs
Access vs trunk ports · 802.1Q · STP · inter-VLAN routing · VLAN hopping · router-on-a-stick · Layer 3 switches
Week 4
Routing & WAN
Static vs dynamic routing · RIP/OSPF/BGP/EIGRP · NAT/PAT · DHCP (DORA, relay) · DNS records · WAN technologies
Week 5
Wireless & Remote Access
802.11 standards · WPA2 vs WPA3 · 802.1X/RADIUS · VPN types (IPSec, SSL) · site surveys · SNMP · syslog
Week 6
Network Security
Firewall types · IDS vs IPS · network attacks (DDoS, MITM, ARP poisoning) · ACLs · DMZ/screened subnet · zero trust
Week 7
Practice Exams (First Pass)
Full-length practice exam · review every wrong answer · identify weak domains · targeted re-study of weak areas
Week 8
Practice Exams & PBQs
2–3 full practice exams · performance-based question practice · final review of port numbers and subnetting · schedule and sit the exam
🎯 The Three Highest-ROI Network+ Study Topics

Subnetting — appears in multiple question formats including performance-based questions. You cannot pass Network+ without being comfortable with subnetting. Practice until you can do it in your head, not just with a formula sheet.

Port numbers — memorise the full port table. Not just HTTP/HTTPS — SNMP (161/162), LDAP (389/636), RADIUS (1812/1813), Kerberos (88), Syslog (514). These appear in firewall rule scenarios, troubleshooting questions, and security questions.

OSI layer identification — given a description of a protocol, device, or problem, you must identify the OSI layer. Switches operate at Layer 2. Routers at Layer 3. Firewalls typically at Layer 3–4 (stateful) or Layer 7 (NGFW). ARP is Layer 2/3. TLS is Layer 5–6. This question type appears on almost every exam.

Performance-Based Questions (PBQs)

The Network+ includes performance-based questions — interactive simulations where you configure a device, draw a network diagram, or troubleshoot a scenario. They appear at the start of the exam. Common PBQ formats on Network+ include:

Network diagram drag-and-drop — place devices in the correct network zones (inside, DMZ, outside). Know where the firewall, web server, DNS server, and workstations belong. IP address configuration — given network requirements, assign correct IPs, subnet masks, and gateways. Subnetting skill is essential. Cable selection — identify the correct cable type (Cat6, fiber SMF/MMF) for a given scenario. Command output interpretation — given ipconfig or tracert output, identify the problem.

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Also On IT Study Hub

Network+ Domain BreakdownDetailed breakdown of all 5 N10-009 domains with study priorities Network+ Cheat SheetQuick reference for exam day — OSI, ports, protocols, subnetting How to Pass Network+Study strategy, recommended resources, and exam tips A+ vs Network+Which to take first and what each certification covers Network+ vs Security+Differences, overlap, and which to pursue after Network+ CompTIA Certifications RoadmapFull certification pathway from A+ through to advanced certs

What to Expect on the Network+ Exam

The N10-009 exam is 90 questions in 90 minutes — a tight pace that rewards candidates who can read scenarios efficiently and recognise what's being tested quickly. Roughly 75–80 questions are multiple choice; the remainder are performance-based questions (PBQs) that appear at the start of the exam. PBQ formats include drag-and-drop topology labelling, IP configuration tasks, cable type matching, and command output interpretation.

The most important tactical preparation: don't spend more than 90 seconds on any multiple-choice question and cap PBQ time at 5 minutes each. Flag questions you're unsure about and return to them. Running out of time is a common failure mode — candidates who get stuck on difficult PBQs at the start often don't complete all the multiple-choice questions.

Passing score is 720 out of 900. The exam is scored on a scaled scoring system, so question difficulty affects point values. Exam questions are not published, but consistently tested areas across candidate reports include: subnetting calculations, VLAN and trunk configuration concepts, wireless standards (802.11ax/Wi-Fi 6 vs predecessors), network troubleshooting command output interpretation, and routing protocol characteristics (OSPF vs RIP vs BGP use cases).

Network+ Study Strategy — Four Weeks to Exam Ready

Candidates with A+ or equivalent background can be ready for Network+ in 6–8 weeks studying 1–2 hours daily. A practical 4-phase approach: Weeks 1–2 — cover Networking Fundamentals (Domain 1) deeply, focusing on OSI/TCP-IP models, subnetting, and ports/protocols. These are the foundation for all other domains and are directly tested at 23% of the exam. Weeks 3–4 — cover Network Implementations (Domain 2) and Network Operations (Domain 3): routing protocols, VLANs, wireless, and network monitoring tools. Weeks 5–6 — cover Network Security (Domain 4) and Network Troubleshooting (Domain 5): attack types, firewall types, and systematic troubleshooting using the OSI model as a guide. Weeks 7–8 — full practice exams, domain-by-domain analysis of weak areas, targeted review, and PBQ-specific drilling.

The most important single skill to develop for Network+: subnetting. Practise daily until you can work any /24 through /30 subnet in under 60 seconds. Use free tools like subnet calculators to check your work, but always do the calculation manually first — the exam won't give you a calculator for subnetting questions.

Is Network+ Worth It?

Network+ is the most widely recognised vendor-neutral networking certification and the most commonly listed requirement for junior to mid-level network administration and IT infrastructure roles. It demonstrates that you understand how networks are designed, how traffic flows, and how to diagnose and fix common network problems — skills that apply regardless of whether the environment runs Cisco, Juniper, Aruba, or any other vendor's equipment.

For candidates who want to move into networking specialisation, Network+ is the stepping stone to vendor-specific credentials like Cisco CCNA. The CCNA builds on the conceptual knowledge Network+ establishes but adds configuration skills (CLI commands, routing protocol configuration, VLAN configuration on real switches). Network+ first, CCNA second is the most common and most logical progression for aspiring network engineers.