CompTIA Network+ (N10-009) Study Guide 2026
$10 · instant PDF download (link also emailed)
For help-desk and junior IT people moving into networking who want a clear path through N10-009 without a 900-page textbook.
Covers CompTIA Network+ N10-009 · Written and maintained by Todd Lavergne, Todd Lavergne Media · Last updated Oct 2026
Network+ rewards understanding over memorizing: subnetting, ports, routing and switching basics, and a troubleshooting method you can apply to scenarios.
- Lessons for all five N10-009 domains
- 80 original practice questions with answers and short explanations
- Subnetting walkthrough, ports table, and symptom-to-cause troubleshooting chart
- Cheat sheet plus 4- and 8-week study plans
- Instant PDF after payment — link also arrives by email
Safe, secure checkout. Pay securely with PayPal or a debit or credit card via PayPal guest checkout.
Download on the thank-you page and by email.
What’s not included
Not a live class, not a video course, and not a promise you will pass. Exam facts are dated October 2026 and cited to official sources inside; always confirm current details with the official exam body before you book.
Disclaimer: an independent PDF study aid, not affiliated with or endorsed by CompTIA. All practice questions are original.
Free sample: 5 questions from the guide
Taken straight from the CompTIA Network+ guide. Try each one, then tap “Show answer.”
At which OSI layer does a switch make forwarding decisions using MAC addresses?
- A) 1
- B) 2
- C) 3
- D) 4
Show answer
Answer: B — Data link layer.
A user's PC shows 169.254.33.10. What is the most likely cause?
- A) DNS failure
- B) DHCP server unreachable
- C) Duplex mismatch
- D) Wrong default gateway
Show answer
Answer: B — APIPA means the PC couldn't get a DHCP lease.
An engineer needs a subnet for a point-to-point router link with no wasted addresses. Best mask?
- A) /24
- B) /29
- C) /30
- D) /32
Show answer
Answer: C — Two usable hosts. (A /31 is also used on some gear, but /30 is the classic answer.)
A cloud resource in a private subnet needs to download updates but must not be reachable from the internet. Use a:
- A) Internet gateway with a public IP
- B) NAT gateway
- C) Load balancer
- D) VPN concentrator
Show answer
Answer: B — Outbound-only access.
Wireless users see −82 dBm signal in a conference room. Best fix?
- A) Add an AP or move one closer
- B) Change DNS
- C) Disable STP
- D) Shorten DHCP lease
Show answer
Answer: A — −82 dBm is weak.
Practice questions are original teaching items, not real exam questions. Independent study aid; not affiliated with or endorsed by the exam provider.
Already studying with a full course such as Professor Messer’s videos or Jason Dion’s course? This $10 guide is a low-cost add-on: a compact review of the exam objectives plus original practice questions with explanations to check what stuck.
Ready when you are.