Quick Answer
The answer is 2 usable IP addresses. A /30 subnet, which corresponds to the subnet mask 255.255.255.252, provides a total of 4 IPv4 addresses, but the first address is reserved as the network identifier and the last as the broadcast address, leaving exactly two addresses available for host devices. This configuration is standard for point-to-point WAN links, like the one described in the CompTIA A+ Core 1 220-1201 exam, where conserving public IPs is critical. On the exam, this concept often appears in scenarios where a technician must determine how many devices can be assigned an IP on a serial link, and the common trap is forgetting to subtract the network and broadcast addresses from the total. A quick memory tip: for a /30, think “30 minus 2 equals 28, but only 2 hosts”—or simply remember that a /30 is the “point-to-point” subnet, giving you just two usable addresses for the two ends of the link.
This 220-1201 practice question tests your understanding of ip addressing. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. 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.
A technician is configuring a new router for a branch office. The ISP provides a public IP of 203.0.113.10/30 for the WAN interface. How many usable IP addresses does the technician have for devices on the WAN link?
2
Correct. A /30 subnet has 2 usable addresses, typically used for the two ends of a point-to-point link.
4
Why wrong: Incorrect. 4 is the total number of addresses in the subnet, but 2 are reserved for network and broadcast.
6
Why wrong: Incorrect. A /29 subnet provides 6 usable addresses, but the question specifies a /30.
1
Why wrong: Incorrect. A /30 provides 2 usable addresses, not 1.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
2
A /30 subnet mask (255.255.255.252) provides 4 total addresses: one network, one broadcast, and two usable. This is commonly used for point-to-point WAN links to conserve public IPs.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
2
Why this is correct
Correct. A /30 subnet has 2 usable addresses, typically used for the two ends of a point-to-point link.
Related concept
CIDR notation defines the prefix length.
4
Why it's wrong here
Incorrect. 4 is the total number of addresses in the subnet, but 2 are reserved for network and broadcast.
6
Why it's wrong here
Incorrect. A /29 subnet provides 6 usable addresses, but the question specifies a /30.
1
Why it's wrong here
Incorrect. A /30 provides 2 usable addresses, not 1.
Common exam traps
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 220-1201 subnetting questions on CIDR, address ranges, and subnet selection.
IP Addressing — study guide chapter
Learn the concepts, then practise the questions
IP Addressing practice questions
Targeted practice on this topic area only
All 220-1201 questions
1,020 questions across all exam domains
CompTIA A+ Core 1 220-1201 study guide
Full concept coverage aligned to exam objectives
220-1201 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise 220-1201 questions linked to Mobile Device Hardware Servicing.
Practise 220-1201 questions linked to Mobile Device Connection Methods.
Practise 220-1201 questions linked to Mobile Device Accessories.
Practise 220-1201 questions linked to Mobile Device Network Connectivity.
Practise 220-1201 questions linked to Mobile Device Application Support.
Practise 220-1201 questions linked to Network Protocols.
Practise 220-1201 questions linked to TCP & UDP Ports.
Practise 220-1201 questions linked to Wireless Networking Technologies.
Practise 220-1201 questions linked to Network Services.
Practise 220-1201 questions linked to Network Configuration Concepts.
Practise 220-1201 questions linked to Common Networking Hardware.
Practise 220-1201 questions linked to IP Addressing.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
IP Addressing — This question tests IP Addressing — CIDR notation defines the prefix length..
The correct answer is: 2 — A /30 subnet mask (255.255.255.252) provides 4 total addresses: one network, one broadcast, and two usable. This is commonly used for point-to-point WAN links to conserve public IPs.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 220-1201 subnetting questions on CIDR, address ranges, and subnet selection.
CIDR notation defines the prefix length.
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 →
Keep practising
Last reviewed: Jun 18, 2026
This 220-1201 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 220-1201 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.