Users on one floor report that they can reach servers on the local network but cannot reach any website. Users on other floors are fine. What is the most likely cause?

The default gateway configured for that floor's VLAN is wrong or unreachable

The floor's switch has lost power

The internet connection is down

A network administrator wants to place the company's public web server so that a compromise of it cannot reach the internal file servers directly. Which design should they use?

Place the web server in a screened subnet (DMZ) between two firewall zones

Put the web server on the same VLAN as the file servers

Give the web server a private IP address only

Disable the web server's logging

Harder than A+ and the cloud fundamentals exams: it expects real understanding of subnetting, routing and troubleshooting, and the performance-based questions cannot be guessed. With a lab and eight to twelve weeks, most people pass.

No. It is recommended, and it helps with the hardware and OS basics, but many people go straight to Network+.

How much does it cost?

About US$369 at the time of writing; prices vary by country, and student and bundle discounts are common. Check CompTIA's store for your region.

How long is it valid?

Three years. You renew by earning continuing education units or by passing a higher CompTIA exam.

Network+ is vendor-neutral and the better first step for general infrastructure roles. CCNA goes deeper and is Cisco-specific; it is the stronger credential for network engineering roles and the harder exam.

All certifications

CompTIA · N10-009 · Entry to intermediate

CompTIA Network+

Vendor-neutral networking: concepts, implementation, operations, security and troubleshooting.

Free practice: 244 questions written to the official exam guide, with the diagnostic, practice papers, timed mocks, a study plan and an explanation on every answer.

Official exam page

Find out where you stand on N10-009

20 questions drawn in the exam’s own domain weights. You get a report straight away: your score against the pass mark, where the points went, and what to study first.

Questions: 20
Time: about 20 minutes
Cost: free

Your email

Your answers save as you go, and the report stays in your record. A new email needs no code.

· your answers stay on this device and you can save the report at the end.

The course

The diagnostic shows where you stand. Then you learn the syllabus chapter by chapter, answer that chapter’s questions, and move on. When every chapter is mastered, you sit full timed mocks in the real exam’s shape.

19 chapters, about 14.5 hours in all. Each is a 45-minute study session with quick checks, then a 10-question quiz on that chapter.

Networking Concepts23% of the exam

The OSI model and network appliances45 min
Cloud concepts and connectivity45 min
Ports, protocols, services and traffic types45 min
Transmission media and transceivers45 min
Topologies, architectures and network types45 min
IPv4 addressing and subnetting45 min
Modern network environments45 min

Network Implementation20% of the exam

Routing technologies45 min
Switching technologies and features45 min
Wireless devices and technologies45 min
Physical installations45 min

Network Operations19% of the exam

Organisational processes and disaster recovery45 min
Network monitoring45 min
Network services, access and management45 min

Network Security14% of the exam

Security concepts and network attacks45 min
Network security features and defences45 min

Network Troubleshooting24% of the exam

Troubleshooting method and cabling issues45 min
Troubleshooting services and performance45 min
Tools and protocols for troubleshooting45 min

About the CompTIA Network+ (N10-009) exam

CompTIA Network+ is the vendor-neutral networking certification that most entry-level infrastructure roles ask for: network technician, junior network administrator, help desk moving into infrastructure, and systems administrators who need networking depth. It certifies that you can design, configure, manage and troubleshoot wired and wireless networks in any vendor's environment.

The current version, N10-009, covers networking concepts (the OSI model, addressing, protocols, cloud networking), implementation (routing, switching, wireless), operations (monitoring, documentation, disaster recovery), security (concepts, attacks, hardening) and troubleshooting, which is the largest domain and includes performance-based questions where you work through a simulated problem.

CompTIA recommends A+ and nine to twelve months of experience, but neither is required. Plan on eight to twelve weeks of study if networking is new to you.

The exam at a glance

Questions: Up to 90 questions, multiple choice and performance-based
Time: 90 minutes
Pass mark: 720 on a scale of 100 to 900
Exam fee: About US$369 (varies by country; academic and voucher discounts exist)
Valid for: 3 years, renewable through continuing education
Where you sit it: Pearson VUE test centre or online proctored
Prerequisites: None required; CompTIA recommends A+ and 9 to 12 months of networking experience

As published in the vendor’s exam guide at the time of writing. Fees vary by country and change; the vendor’s page is the source of truth.

The fee and how to sit it in your country: Sri Lanka · India · Pakistan · Bangladesh · Nepal · Australia · New Zealand · Philippines · Indonesia · Vietnam

What is on the exam, domain by domain

Networking Concepts
The OSI model layer by layer, IPv4 and IPv6 addressing and subnetting, common ports and protocols, network topologies, cloud and virtual networking, and the physical media.
23% of the paper
Network Implementation
Routing (static, OSPF, BGP basics), switching (VLANs, trunking, spanning tree), wireless standards and configuration, and IP services such as DHCP and DNS.
20% of the paper
Network Operations
Monitoring and SNMP, logs and baselines, documentation, change management, business continuity and disaster recovery.
19% of the paper
Network Security
The CIA triad, authentication and access control, common attacks, segmentation, firewalls, VPNs and device hardening.
14% of the paper
Network Troubleshooting
The largest domain. A methodology, then cabling, wireless, addressing, routing and performance problems, and the tools (ping, traceroute, nslookup, ipconfig, wireshark) that find them. Performance-based questions live here.
24% of the paper

How to prepare

Read the objectives document from CompTIA and turn it into a checklist; the exam does not stray from it.
Learn subnetting until it is mechanical. It appears in several domains and it is the most common reason people run out of time.
Build a lab: Packet Tracer or GNS3 for routing and switching, a home router for wireless and DHCP, Wireshark on your own traffic. The performance-based questions assume you have done these things.
Memorise the port and protocol table (DNS 53, DHCP 67/68, HTTP 80, HTTPS 443, SSH 22, RDP 3389 and the rest). Questions assume it.
Practise the troubleshooting method as a sequence: identify the problem, establish a theory, test it, plan and implement, verify, document. Questions ask for the next step.
Two timed practice papers above your target before booking; the time limit is tight with performance-based questions.

Sample questions

Three questions in the exam’s style, written by Square 1 against the published domains. They are ours, not the vendor's. The answer and the reasoning are under each one; the practice papers on this page draw from a bank written the same way, with an explanation on every question.

Question 1 · Networking Concepts
A host has the IP address 192.168.10.77 with a subnet mask of 255.255.255.192. What is the network address of its subnet?
1. 192.168.10.0
2. 192.168.10.64
3. 192.168.10.96
4. 192.168.10.128
Answer: B. A /26 mask (255.255.255.192) makes subnets of 64 addresses: 0 to 63, 64 to 127, 128 to 191, 192 to 255. The host .77 falls in the 64 to 127 block, so the network address is 192.168.10.64.
Question 2 · Network Troubleshooting
Users on one floor report that they can reach servers on the local network but cannot reach any website. Users on other floors are fine. What is the most likely cause?
1. A DNS server outage
2. The floor's switch has lost power
3. The default gateway configured for that floor's VLAN is wrong or unreachable
4. The internet connection is down
Answer: C. Local reachability works and only one floor is affected, which rules out the switch and the shared internet link. Reaching the local network but nothing beyond it is the signature of a missing or wrong default gateway. A DNS outage would affect everyone.
Question 3 · Network Security
A network administrator wants to place the company's public web server so that a compromise of it cannot reach the internal file servers directly. Which design should they use?
1. Put the web server on the same VLAN as the file servers
2. Place the web server in a screened subnet (DMZ) between two firewall zones
3. Give the web server a private IP address only
4. Disable the web server's logging
Answer: B. A screened subnet isolates public-facing hosts from the internal network with firewall rules on both sides, so a compromised web server cannot reach internal servers directly. Sharing a VLAN removes that boundary; a private address alone does not segment; disabling logging makes things worse.

Questions people ask before they book

Is Network+ hard?: Harder than A+ and the cloud fundamentals exams: it expects real understanding of subnetting, routing and troubleshooting, and the performance-based questions cannot be guessed. With a lab and eight to twelve weeks, most people pass.
Do I need A+ first?: No. It is recommended, and it helps with the hardware and OS basics, but many people go straight to Network+.
How much does it cost?: About US$369 at the time of writing; prices vary by country, and student and bundle discounts are common. Check CompTIA's store for your region.
How long is it valid?: Three years. You renew by earning continuing education units or by passing a higher CompTIA exam.
Network+ or CCNA?: Network+ is vendor-neutral and the better first step for general infrastructure roles. CCNA goes deeper and is Cisco-specific; it is the stronger credential for network engineering roles and the harder exam.