N10-009 Network Security Practice Question
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?
⚠ Common exam trap
The trap here is that 802.11i sounds security-related and is often confused with 802.1X because both involve authentication, but 802.11i is strictly for wireless encryption (WPA2) and does not control port-based access on wired networks.
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
✓
802.1X
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.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
802.11i
Why it's wrong here
802.11i is a security standard specifically designed for wireless local area networks (WLANs), forming the basis for Wi-Fi Protected Access 2 (WPA2). It defines robust encryption and authentication protocols, primarily utilizing the Advanced Encryption Standard (AES) and improved key management, to secure wireless communications. Although it provides authentication for wireless clients, 802.11i is not applicable to wired network access control or port-based authentication mechanisms.
When this WOULD be correct
This option would be correct if the question asked about securing a wireless LAN (WLAN) with strong encryption and authentication, such as implementing WPA2-Enterprise on a Wi-Fi network.
- ✓
802.1X
Why this is correct
802.1X provides robust port-based authentication for both wired and wireless networks, acting as a critical component for Network Access Control (NAC). It leverages an authenticator (like a switch or access point) to control network access based on successful authentication by an external server, typically RADIUS. This standard ensures that only authenticated and authorized devices or users can connect to the network, preventing unauthorized access at the network edge.
- ✗
802.3af
Why it's wrong here
802.3af is the IEEE standard for Power over Ethernet (PoE), which enables network devices to receive electrical power along with data over standard Ethernet cabling. This standard specifies how power sourcing equipment (PSE), such as PoE-enabled switches, can deliver up to 15.4 watts of DC power to powered devices (PDs) like IP phones, wireless access points, or security cameras. Its sole purpose is power delivery, and it has no function related to network access control or authentication.
When this WOULD be correct
802.3af would be the correct answer if the question asked about a standard for supplying power to devices like IP cameras or wireless access points over Ethernet cables, without needing separate power sources.
- ✗
802.1Q
Why it's wrong here
802.1Q is the IEEE standard for VLAN tagging, which enables the creation of Virtual Local Area Networks (VLANs) across multiple switches using trunk links. Its primary function is to insert a VLAN identifier into Ethernet frames, allowing network traffic to be segmented and isolated into different broadcast domains. While essential for network segmentation and traffic management, 802.1Q does not provide any mechanism for authenticating users or devices to gain initial network access.
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.
✓802.1XCorrect answer▾
Why this is correct
802.1X provides robust port-based authentication for both wired and wireless networks, acting as a critical component for Network Access Control (NAC). It leverages an authenticator (like a switch or access point) to control network access based on successful authentication by an external server, typically RADIUS. This standard ensures that only authenticated and authorized devices or users can connect to the network, preventing unauthorized access at the network edge.
✗802.11iWrong answer — click to see why▾
Why this is wrong here
802.11i is a security standard for wireless networks (WPA2), not for wired network access control. The question specifies a wired network, making 802.1X the correct choice for port-based authentication.
★ When this WOULD be the correct answer
This option would be correct if the question asked about securing a wireless LAN (WLAN) with strong encryption and authentication, such as implementing WPA2-Enterprise on a Wi-Fi network.
Why candidates choose this
Candidates may confuse 802.11i with 802.1X because both involve authentication and security, but 802.11i is specific to wireless, while the question is about wired networks.
✗802.3afWrong answer — click to see why▾
Why this is wrong here
802.3af is the Power over Ethernet (PoE) standard, which defines how power is delivered over Ethernet cabling. It does not provide network access control or authentication, so it is irrelevant to enforcing NAC with RADIUS.
★ When this WOULD be the correct answer
802.3af would be the correct answer if the question asked about a standard for supplying power to devices like IP cameras or wireless access points over Ethernet cables, without needing separate power sources.
Why candidates choose this
Candidates may confuse 802.3af with 802.1X because both are IEEE standards related to networking, and the 'af' suffix might be misremembered as an authentication-related standard.
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?”
Quick reference
AAA Protocol Comparison
| Protocol | Port(s) | Encryption | Transport | Primary Use |
|---|---|---|---|---|
| RADIUS | 1812 / 1813 | Password only | UDP | Network access control |
| TACACS+ | 49 | Full packet | TCP | Device administration |
| Diameter | 3868 | Full session | TCP / SCTP | Carrier / mobile networks |
| 802.1X | — | EAP-based | Layer 2 | Port-based access control |
TACACS+ encrypts the entire packet; RADIUS only encrypts the password field — a key exam distinction.
Go deeper
Related to this question
Learn chapter
Network Device Hardening
Key term
Wireless LAN
A Wireless LAN (WLAN) is a network that connects devices like laptops and phones to each other and the internet using radio waves instead of physical cables.
Key term
LAN
Local Area Network — a network confined to a single physical location such as an office, building, or campus.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.