- A
169.254.1.1
Why wrong: This is an APIPA address used when DHCP fails. It is not part of the private ranges defined by RFC 1918.
- B
172.32.1.1
Why wrong: 172.32.1.1 is not within the 172.16.0.0/12 private range (which ends at 172.31.255.255). It is a public address.
- C
192.168.1.1
192.168.1.1 belongs to the 192.168.0.0/16 private address range, commonly used in home and small business networks.
- D
172.15.1.1
Why wrong: 172.15.1.1 is below the 172.16.0.0/12 range and is a public IP address.
Question 386 of 520
Private IPv4 Addresses — RFC 1918 Ranges | Network+ Explained
This N10-009 practice question tests your understanding of networking concepts. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. A key principle to apply: rFC 1918. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which of the following IP addresses is a private IP address as defined by RFC 1918?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
192.168.1.1
Option C (192.168.1.1) is correct because RFC 1918 reserves the 192.168.0.0/16 block (192.168.0.0 – 192.168.255.255) for private use within local networks. This address is not routable on the public internet, making it suitable for internal LAN addressing.
Key principle: RFC 1918
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
169.254.1.1
- ✗
172.32.1.1
Why it's wrong here
172.32.1.1 is not within the 172.16.0.0/12 private range (which ends at 172.31.255.255). It is a public address.
When this WOULD be correct
This IP would be correct if the question asked for a public IP address or an IP that is not in any private range. For example, 'Which of the following is a public IP address?'
- ✓
192.168.1.1
Why this is correct
192.168.1.1 belongs to the 192.168.0.0/16 private address range, commonly used in home and small business networks.
Related concept
RFC 1918
- ✗
172.15.1.1
Why it's wrong here
172.15.1.1 is below the 172.16.0.0/12 range and is a public IP address.
When this WOULD be correct
This option would be correct if the question asked for a public IP address or an IP address that is not in the RFC 1918 private ranges, as 172.15.1.1 is a public IP.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓192.168.1.1Correct answer▾
Why this is correct
192.168.1.1 belongs to the 192.168.0.0/16 private address range, commonly used in home and small business networks.
✗169.254.1.1Wrong answer — click to see why▾
Why this is wrong here
169.254.1.1 is an APIPA address, not a private IP per RFC 1918. RFC 1918 defines private ranges as 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.
★ When this WOULD be the correct answer
This would be correct if the question asked for an APIPA address used for automatic private IP addressing when DHCP fails.
Why candidates choose this
Candidates may confuse APIPA (169.254.0.0/16) with private IP ranges because both are non-routable on the public internet.
✗172.32.1.1Wrong answer — click to see why▾
Why this is wrong here
172.32.1.1 falls within the 172.16.0.0/12 range (172.16.0.0 to 172.31.255.255) only if the second octet is between 16 and 31. Since 32 is outside that range, it is not a private IP per RFC 1918.
★ When this WOULD be the correct answer
This IP would be correct if the question asked for a public IP address or an IP that is not in any private range. For example, 'Which of the following is a public IP address?'
Why candidates choose this
Candidates may mistakenly think that any IP starting with 172 is private, not realizing that only the 172.16.0.0/12 block is reserved.
✗172.15.1.1Wrong answer — click to see why▾
Why this is wrong here
172.15.1.1 falls within the 172.16.0.0/12 range (172.16.0.0 to 172.31.255.255) defined by RFC 1918 for private IP addresses, but 172.15.1.1 is actually in the 172.8.0.0/13 range, which is not private; it is a public IP address.
★ When this WOULD be the correct answer
This option would be correct if the question asked for a public IP address or an IP address that is not in the RFC 1918 private ranges, as 172.15.1.1 is a public IP.
Why candidates choose this
Candidates may mistakenly think that all 172.x.x.x addresses are private, not realizing that only the 172.16.0.0/12 block is reserved, and 172.15.1.1 is just outside that range.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often remember 172.x.x.x as private but forget the specific range (172.16.0.0/12), leading them to select 172.32.1.1 or 172.15.1.1, both of which are public addresses.
Detailed technical explanation
How to think about this question
RFC 1918 defines three private IPv4 address blocks: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The 172.16.0.0/12 block spans from 172.16.0.0 to 172.31.255.255, meaning only addresses where the second octet is between 16 and 31 inclusive are private; 172.32.1.1 and 172.15.1.1 fall outside this range. In real-world scenarios, misconfiguring a router with a non-private RFC 1918 address can cause routing loops or internet unreachability if the address is actually public and routable.
KKey Concepts to Remember
- RFC 1918
- Private IP address
- 192.168.0.0/16
- 172.16.0.0/12
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
RFC 1918
Real-world example
How this comes up in practice
A practitioner preparing for the N10-009 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. RFC 1918 Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Review rFC 1918, then practise related N10-009 questions on the same topic to reinforce the concept.
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FAQ
Questions learners often ask
What does this N10-009 question test?
Networking Concepts — This question tests Networking Concepts — RFC 1918.
What is the correct answer to this question?
The correct answer is: 192.168.1.1 — Option C (192.168.1.1) is correct because RFC 1918 reserves the 192.168.0.0/16 block (192.168.0.0 – 192.168.255.255) for private use within local networks. This address is not routable on the public internet, making it suitable for internal LAN addressing.
What should I do if I get this N10-009 question wrong?
Review rFC 1918, then practise related N10-009 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
RFC 1918
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more ways this is tested on N10-009
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network engineer is reviewing RFC 1918 address ranges to plan a private IP addressing scheme. Which of the following IP addresses falls within the private address space for Class A?
medium- A.172.16.0.1
- B.192.168.1.1
- ✓ C.10.10.10.1
- D.172.32.0.1
Why C: Option C is correct because RFC 1918 defines the Class A private address range as 10.0.0.0/8, which includes all addresses from 10.0.0.0 to 10.255.255.255. 10.10.10.1 falls within this range, making it a valid private IP address for internal network use.
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Last reviewed: Jun 11, 2026
This N10-009 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the N10-009 exam.
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