Network+ / practice questions
CompTIA Network+ Practice Questions, With the Reasoning Explained
Network+ leans hard on two things: addressing math you can do under time pressure, and troubleshooting logic that starts at the right layer. Both improve with reps rather than reading.
Six questions below in the exam's style, with the answer and the why after each.
Pick an option to lock it in and see the reasoning straight away. Nothing is timed and nothing is recorded, so answer the way you would on the day rather than the way that looks good.
Question 1
How many usable host addresses are available in the 192.168.10.0/26 subnet?
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B. 62
A /26 leaves six host bits, so 2^6 gives 64 addresses, minus the network address and the broadcast address, leaving 62 usable. Get comfortable going from prefix length to host count in your head, because subnetting questions are guaranteed points that many people leave on the table by rushing the arithmetic.
Question 2
A workstation that normally gets its address automatically comes up with 169.254.18.7. What does this indicate?
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B. The client could not reach a DHCP server and self-assigned an APIPA address
The 169.254.0.0/16 range is APIPA, which a client self-assigns when its DHCP discovery gets no answer. That points you at the DHCP path: the server itself, the scope being exhausted, or a missing relay on a routed segment. It also tells you the NIC and the local link are alive, which narrows the search considerably.
Question 3
One user can reach a server by IP address but not by hostname. Everything else on the network works. What should you check first?
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B. DNS resolution on that client
Reaching the IP proves routing, the physical path and the server are all fine, so the failure is name to address translation. Check the client's DNS server settings, its local hosts file and its resolver cache. The habit worth building is exactly this: use what already works to eliminate layers before you touch anything.
Question 4
Which port does SSH use for secure remote command line access?
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B. 22
SSH is TCP 22. Port 23 is Telnet, which sends everything including credentials in clear text and should not be in service. Port 21 is FTP control, and 3389 is RDP for remote desktop. Exam questions often pair a secure protocol with its legacy insecure twin, so learn them as pairs: 22 versus 23, 443 versus 80, 990 or 22 versus 21.
Question 5
In a 2.4 GHz wireless deployment in North America, which channel set is used to avoid overlapping channel interference?
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B. 1, 6, 11
Channels 1, 6 and 11 are the only three that do not overlap in the 2.4 GHz band, because each channel is wider than the spacing between channel numbers. Neighboring access points on channels 3 and 5 will interfere even though the numbers look distinct. Note the tradeoff the plan is making: with only three non-overlapping channels, a dense site ends up reusing them, so you accept co-channel interference (access points on the same channel taking turns) in order to avoid adjacent channel interference (access points talking over each other), which is the more damaging of the two. The 5 GHz band has many more non-overlapping channels, which is a large part of why it performs better in dense sites.
Question 6
At which OSI layer does a traditional network switch make its forwarding decisions?
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B. Layer 2
A standard switch forwards on MAC addresses, which is Layer 2. A hub just repeats electrical signals at Layer 1, and a router forwards on IP addresses at Layer 3. Multilayer or Layer 3 switches blur the line by doing routing in hardware, and the exam expects you to know that the plain word 'switch' means Layer 2 unless it says otherwise.
Six questions is a sample, not a study plan
Any fixed list of questions has the same problem: work it twice and you are remembering the list rather than learning the material. Techunique generates every scenario fresh against the CompTIA Network+ (N10-009) blueprint, ladders the difficulty to how you are answering, and explains each miss the moment you make it. One full session is free every day.
Practice for the CompTIA Network+ exam. Techunique is not affiliated with CompTIA.
How to get value out of practice questions
- Drill subnetting until you can convert prefix to host count and back without paper. It is the highest-yield skill on the exam.
- Learn the port list in secure and insecure pairs. It makes both the ports and the security material stick.
- For every troubleshooting question, name the OSI layer you are testing before you pick an answer.
- Performance-based questions come first and eat clock. Flag them, do the multiple choice, then come back.
Keep reading
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How to Pass Security+ When the Acronyms Start Blurring
A working study approach for CompTIA Security+: what the exam really tests, why memorizing acronyms fails, and how to train scenario thinking.
CompTIA Network+ Study Guide: What to Learn and In What Order
How the N10-009 exam is weighted, the topics that decide pass or fail, and a study order that builds each layer on the one before it.