Which Authentication Component Is Required for Wired and Wireless NAC?

N10-008 By islever Editorial Last updated

Short answer

B 802.1X

Question

A company's management team wants to implement NAC on the wired and wireless networks. Which of the following is an authentication component that must be used in this solution?
  1. IPSec
  2. 802.1X Correct Answer
  3. EAP
  4. TACACS+

Key Takeaways

Tests understanding of NAC frameworks, with the common trap being the confusion between 802.1X (the port-control protocol) and EAP (the underlying authentication method).

Implementing Network Access Control (NAC) requires a standardized port-based authentication mechanism to secure both wired and wireless endpoints. The community unanimously agrees that IEEE 802.1X is the mandatory foundational component for this architecture.

Common mistake: Option C (EAP) is frequently selected because it handles credential exchange, but it functions only as an authentication framework layered inside 802.1X rather than the NAC enforcement protocol itself.

Expert Analysis

Why the Answer Is Correct

802.1X is the IEEE standard for port-based network access control, serving as the mandatory authentication backbone for modern NAC deployments. It ensures that devices cannot communicate on the network until their identity is verified by an authentication server. Top-voted discussions confirm that 802.1X directly bridges identity verification with physical and logical port control.

Why the Other Options Are Wrong

IPSec secures data in transit through encryption and peer authentication but does not manage initial network access rights. EAP is an authentication framework that facilitates credential validation but lacks the port-enforcement capabilities required for NAC. TACACS+ is exclusively designed for authenticating and authorizing administrative access to network infrastructure devices, not end-user endpoints.

Community Comment Notes

Users consistently validate 802.1X as the definitive NAC component, emphasizing its role in enforcing access policies before connectivity is granted. Comment [2] effectively breaks down why IPSec and EAP do not fulfill the NAC requirement, while comment [3] highlights its integration with policy enforcement engines. The consensus reinforces that while EAP handles the math of authentication, 802.1X provides the necessary architectural gatekeeping.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When studying NAC architectures, clearly separate the access control framework (802.1X), the authentication method (EAP), and the backend database (RADIUS). Focusing on the handshake sequence and the specific responsibility of each component will prevent overlap errors on certification exams.

Community Votes

B
100%

100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 3 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 3

  1. igorclapa 👍 6
    NAC = network access control = 802.1X for wireless authentication
  2. a87d6a4 👍 4 Answered B
    802.1X is a network access control (NAC) protocol used for authenticating devices on wired and wireless networks. It provides a framework for port-based network access control and is crucial for implementing NAC solutions. A. IPSec: IPSec is used for securing IP communications through encryption and authentication but is not specifically for network access control. C. EAP: Extensible Authentication Protocol (EAP) is an authentication framework used in conjunction with 802.1X but is not a standalone NAC component. D. TACACS+: TACACS+ (Terminal Access Controller Access-Control System Plus) is an authentication protocol used for network device management but is not specific to NAC for wired and wireless networks.
  3. dadba8c 👍 2
    B. 802.1X 802.1X is a network access control protocol that is widely used for authenticating devices and users on wired and wireless networks. It provides a framework for enforcing access control policies by authenticating devices before they can access the network. 802.1X is commonly integrated with NAC solutions to ensure that only authenticated and authorized users and devices can connect to the network. EAP (Extensible Authentication Protocol) (Option C) is a framework used by 802.1X to support various authentication methods. However, EAP is not a standalone authentication mechanism; it works within 802.1X. IPSec (Option A) is a suite of protocols for securing IP communications, typically used for VPNs, but it is not directly involved in the NAC authentication process. TACACS+ (Option D) is an authentication protocol used for centralized authentication of users to network devices (e.g., routers, switches), but it is not a component specifically required for NAC. Therefore, 802.1X is the correct choice as the authentication component that must be used when implementing NAC on both wired and wireless networks.

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