The answer is 802.1X, the IEEE standard for port-based network access control (PNAC). This standard is correct because it uses the Extensible Authentication Protocol (EAP) to authenticate users at the switch port level, requiring valid domain credentials before granting full network access to a wired or wireless LAN. On the CompTIA Network+ N10-009 exam, this question tests your understanding of how 802.1X enforces authentication at Layer 2, often appearing in scenarios involving corporate networks that integrate with RADIUS servers and Active Directory. A common trap is confusing 802.1X with MAC filtering or captive portals—remember that 802.1X authenticates the user, not the device’s MAC address. Memory tip: think “1X = one user, one port, one authentication.”
N10-009 Network Security Practice Question
This N10-009 practice question tests your understanding of network security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 company is implementing network access control to ensure only authenticated users can connect to the wired network. Users must authenticate using their domain credentials before gaining full network access. Which standard should be implemented?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
802.1X
802.1X is the IEEE standard for port-based network access control (PNAC). It uses the Extensible Authentication Protocol (EAP) to authenticate devices attempting to connect to a wired or wireless LAN, requiring valid domain credentials before the switch port grants full network access.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
802.1X
Why this is correct
802.1X provides authentication for devices attempting to connect to a network port, verifying credentials against a central server.
Related concept
Read the scenario before looking for a memorised answer.
✗
802.3af
Why it's wrong here
802.3af is the Power over Ethernet (PoE) standard, not related to authentication.
✗
802.11i
Why it's wrong here
802.11i is a wireless security standard (WPA2), not applicable to wired network authentication.
✗
802.1Q
Why it's wrong here
802.1Q is the VLAN tagging standard, used for trunking, not authentication.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests 802.1X by contrasting it with 802.11i, trapping candidates who confuse wireless security standards with wired port-based access control.
Detailed technical explanation
How to think about this question
802.1X operates in a three-role model: supplicant (client), authenticator (switch), and authentication server (RADIUS, e.g., Cisco ISE or Microsoft NPS). The switch initially places the port in an unauthorized state, allowing only EAPOL (EAP over LAN) frames; only after successful authentication does the switch open the port for normal traffic, often dynamically assigning a VLAN based on RADIUS attributes.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
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
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
Network Security — This question tests Network Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: 802.1X — 802.1X is the IEEE standard for port-based network access control (PNAC). It uses the Extensible Authentication Protocol (EAP) to authenticate devices attempting to connect to a wired or wireless LAN, requiring valid domain credentials before the switch port grants full network access.
What should I do if I get this N10-009 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Variation 1. A company wants to enforce network access control such that only authenticated users can connect to the wired network. The authentication server will use RADIUS. Which IEEE standard should be implemented?
medium
A.802.11i
✓ B.802.1X
C.802.3af
D.802.1Q
Why B: 802.1X is the IEEE standard for port-based network access control (PNAC). It provides a framework for authenticating devices before granting access to a wired or wireless LAN, using an authentication server such as RADIUS. This directly meets the requirement to enforce network access control so that only authenticated users can connect to the wired network.
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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.
Question Discussion
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