easyMultiple ChoiceObjective-mapped
220-1102 Practice Question: A customer calls saying their home Wi-Fi network…
A customer calls saying their home Wi-Fi network suddenly stopped working after they changed the router's security mode from WPA2-PSK to WPA2-Enterprise. All their devices previously connected fine. What is the most likely cause of the problem?
⚠ Common exam trap
In the CompTIA A+ exam, it's important to distinguish between WPA2-PSK (pre-shared key, no server) and WPA2-Enterprise (requires a RADIUS/AAA server). The trap here is that candidates may assume all WPA2 modes work identically or blame encryption cipher support instead of the missing authentication infrastructure.
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
✓
The router is now requiring a username and password from a RADIUS server, which the home network lacks.
WPA2-Enterprise uses 802.1X authentication, which requires a RADIUS server to validate credentials (username and password). Home routers typically lack a built-in RADIUS server, so after changing to WPA2-Enterprise, the router cannot authenticate any client, causing all devices to fail to connect. The previous WPA2-PSK mode used a simple pre-shared key, which worked without any external server.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The router's firmware is outdated.
Why it's wrong here
Outdated firmware can indeed lead to various network instabilities, performance issues, or security vulnerabilities. However, the problem's sudden appearance immediately after a user-initiated change to the security mode strongly suggests a direct consequence of that configuration alteration, rather than a pre-existing or latent firmware bug. While a firmware update might be good general maintenance, it's not the most direct or probable cause for a connectivity failure specifically tied to a security mode change.
- ✗
The devices do not support the new encryption cipher.
Why it's wrong here
WPA2-Enterprise, like WPA2-Personal (PSK), primarily utilizes the Advanced Encryption Standard (AES) for data confidentiality, which is a widely adopted and supported encryption cipher across virtually all modern Wi-Fi devices. The issue is not with the encryption method itself, but rather with the underlying authentication mechanism. Devices are likely failing to establish a connection because they cannot complete the necessary authentication steps, not because they lack support for AES.
- ✓
The router is now requiring a username and password from a RADIUS server, which the home network lacks.
Why this is correct
WPA2-Enterprise mode is designed for corporate or institutional environments, leveraging 802.1X authentication to provide centralized user management and stronger security. This mode requires a Remote Authentication Dial-In User Service (RADIUS) server to validate user credentials (username and password) for each device attempting to connect. Standard home networks lack the complex infrastructure of a dedicated RADIUS server, meaning client devices cannot complete the required authentication handshake, leading to connection failures.
- ✗
The SSID was changed during the configuration.
Why it's wrong here
If the Service Set Identifier (SSID), or network name, had been changed, devices would simply no longer see the old network name and would need to be manually reconfigured to connect to the new SSID. However, the customer's description specifically states they changed the "security mode," implying the SSID remained the same. The problem is not that the network is invisible or renamed, but that devices cannot successfully authenticate to the existing network.
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
Virtualization and Client-Side
Key term
Authentication
Authentication is the process of verifying that someone or something is who or what it claims to be before granting access to a system or resource.
Key term
RADIUS
RADIUS is a network protocol that provides centralized authentication, authorization, and accounting management for users who connect and use a network service.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1202 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 220-1202 exam.