N10-009 Network Security Practice Question

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

  IEEE 802.1X is a port-based network access control standard designed to prevent unauthorized devices from connecting to a wired or wireless LAN. It enforces authentication before granting network access by using the Extensible Authentication Protocol (EAP) between a supplicant (the client device), an authenticator (typically a switch or access point), and an authentication server (usually RADIUS). This process ensures that only authenticated and authorized users or devices can access network resources, effectively securing the physical access layer.

• ✗

  802.11i

  Why it's wrong here

  IEEE 802.11i is a robust wireless security standard that specifies the security mechanisms for Wi-Fi networks, most notably defining Wi-Fi Protected Access 2 (WPA2). It provides strong encryption using AES-CCMP and robust authentication methods, including 802.1X/EAP for enterprise environments or pre-shared keys for personal use, to secure wireless communications. However, 802.11i is exclusively designed for wireless local area networks (WLANs) and is not applicable for securing or authenticating devices connected to wired Ethernet ports.

  When this WOULD be correct

  If the question asked about securing a wireless LAN against unauthorized access, 802.11i (WPA2) would be the correct answer. For example: 'A company wants to implement strong encryption and authentication for its Wi-Fi network. Which IEEE standard should be used?'

• ✗

  802.3af

  Why it's wrong here

  IEEE 802.3af defines the Power over Ethernet (PoE) standard, which allows electrical power to be delivered to network devices over the same Ethernet cable that carries data. This standard is specifically designed to power devices such as IP phones, wireless access points, and security cameras without requiring separate power outlets. 802.3af is solely concerned with power delivery and does not incorporate any features for authenticating devices or controlling network access based on security policies.

  When this WOULD be correct

  A question asking: 'Which IEEE standard allows Ethernet switches to deliver power to devices such as IP cameras and VoIP phones?' would make 802.3af the correct answer.

• ✗

  802.1Q

  Why it's wrong here

  IEEE 802.1Q is the standard for Virtual Local Area Network (VLAN) tagging, which enables a single physical network infrastructure to support multiple logical broadcast domains. Its primary function is to insert a tag into Ethernet frames, identifying which VLAN the frame belongs to, allowing switches to properly forward traffic across trunk links. While it provides network segmentation and traffic isolation, 802.1Q does not offer any mechanism for device authentication or access control to prevent unauthorized connections.

  When this WOULD be correct

  A network administrator needs to segment traffic on a trunk link between switches to separate different departments' traffic. Implementing 802.1Q VLAN tagging would be the correct answer.

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.

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?”

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