- A
The tablets have the wrong date and time set.
Why wrong: Incorrect date/time can cause certificate validation failures, but the most direct missing piece is the CA certificate itself.
- B
The tablets are missing the root CA certificate in their trusted store.
For 802.1X with certificates, the device must trust the CA that signed the server certificate; without it, the handshake fails.
- C
The tablets are using WPA2-Personal instead of WPA2-Enterprise.
Why wrong: The technician already verified security settings, so this is unlikely.
- D
The tablets have a static IP configured that conflicts with the DHCP scope.
Why wrong: IP configuration issues would occur after authentication, not prevent the initial connection.
Question 874 of 1,020
Troubleshooting 802.1X Certificate Authentication on Tablets
This 220-1201 practice question tests your understanding of mobile device network connectivity. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 technician is deploying a fleet of tablets that must connect to a corporate network using 802.1X authentication with certificates. After configuring the Wi-Fi profile, some tablets fail to connect. The technician verifies the SSID and security settings are correct. What is the most likely missing configuration?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Quick Answer
The answer is that the tablets are missing the root CA certificate in their trusted store. This is correct because 802.1X certificate authentication requires the client device to validate the server’s identity by checking the server certificate against a trusted root certificate authority; without the CA certificate installed, the tablet cannot complete the trust chain and will reject the connection. On the CompTIA A+ Core 1 220-1201 exam, this scenario tests your understanding of PKI fundamentals and how certificate-based network authentication works, often appearing as a trap where you might mistakenly blame the SSID or security settings. A common memory tip is “No root, no route”—if the root CA is missing, the device has no trusted anchor to verify the server, so authentication fails.
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 tablets are missing the root CA certificate in their trusted store.
802.1X authentication using EAP-TLS requires the client to validate the server's certificate against a trusted root CA. If the root CA certificate is missing from the tablet's trusted store, the client cannot verify the RADIUS server's identity, causing the EAP-TLS handshake to fail. This is the most likely issue since the SSID and security settings are already confirmed correct.
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.
- ✗
The tablets have the wrong date and time set.
Why it's wrong here
Incorrect date/time can cause certificate validation failures, but the most direct missing piece is the CA certificate itself.
- ✓
The tablets are missing the root CA certificate in their trusted store.
Why this is correct
For 802.1X with certificates, the device must trust the CA that signed the server certificate; without it, the handshake fails.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The tablets are using WPA2-Personal instead of WPA2-Enterprise.
Why it's wrong here
The technician already verified security settings, so this is unlikely.
- ✗
The tablets have a static IP configured that conflicts with the DHCP scope.
Why it's wrong here
IP configuration issues would occur after authentication, not prevent the initial connection.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The 220-1201 exam often tests the distinction between authentication failures due to missing root CA versus certificate expiration or date/time issues, trapping candidates who assume a simple time sync problem when the real issue is a missing trust anchor.
Detailed technical explanation
How to think about this question
In 802.1X with EAP-TLS, the client (supplicant) and RADIUS server exchange certificates during the TLS handshake. The client must trust the server's certificate by having the issuing root CA certificate in its trusted store; without it, the client sends a fatal alert and aborts the connection. Real-world deployments often use Microsoft NPS or FreeRADIUS, and forgetting to distribute the CA certificate via MDM or GPO is a common oversight.
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 junior network technician can log in to a core router but cannot reach the enable prompt or configuration mode. The AAA server is authenticating the login — but the authorisation policy only grants privilege level 1, not 15. Authentication (who you are) is working; authorisation (what you can do) is not.
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.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Mobile Device Network Connectivity — study guide chapter
Learn the concepts, then practise the questions
- →
Mobile Device Network Connectivity practice questions
Targeted practice on this topic area only
- →
All 220-1201 questions
1,020 questions across all exam domains
- →
CompTIA A+ Core 1 220-1201 study guide
Full concept coverage aligned to exam objectives
- →
220-1201 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 220-1201 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Mobile Device Hardware Servicing practice questions
Practise 220-1201 questions linked to Mobile Device Hardware Servicing.
Mobile Device Connection Methods practice questions
Practise 220-1201 questions linked to Mobile Device Connection Methods.
Mobile Device Accessories practice questions
Practise 220-1201 questions linked to Mobile Device Accessories.
Mobile Device Network Connectivity practice questions
Practise 220-1201 questions linked to Mobile Device Network Connectivity.
Mobile Device Application Support practice questions
Practise 220-1201 questions linked to Mobile Device Application Support.
Network Protocols practice questions
Practise 220-1201 questions linked to Network Protocols.
TCP & UDP Ports practice questions
Practise 220-1201 questions linked to TCP & UDP Ports.
Wireless Networking Technologies practice questions
Practise 220-1201 questions linked to Wireless Networking Technologies.
Network Services practice questions
Practise 220-1201 questions linked to Network Services.
Network Configuration Concepts practice questions
Practise 220-1201 questions linked to Network Configuration Concepts.
Common Networking Hardware practice questions
Practise 220-1201 questions linked to Common Networking Hardware.
IP Addressing practice questions
Practise 220-1201 questions linked to IP Addressing.
Practice this exam
Start a free 220-1201 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 220-1201 question test?
Mobile Device Network Connectivity — This question tests Mobile Device Network Connectivity — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The tablets are missing the root CA certificate in their trusted store. — 802.1X authentication using EAP-TLS requires the client to validate the server's certificate against a trusted root CA. If the root CA certificate is missing from the tablet's trusted store, the client cannot verify the RADIUS server's identity, causing the EAP-TLS handshake to fail. This is the most likely issue since the SSID and security settings are already confirmed correct.
What should I do if I get this 220-1201 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More 220-1201 practice questions
- During a network cable installation, a technician needs to verify that a newly run Cat6 cable is properly terminated and…
- A user connects a 4K monitor to their laptop using a USB-C port. The monitor is detected, but the resolution is stuck at…
- A technician is troubleshooting a laptop that will not charge. The battery is removable, and the power adapter works on…
- A customer brings in a smartphone with a broken charging port. They want the port replaced. During disassembly, the tech…
- A user reports that their laptop's keyboard types random characters when certain keys are pressed. The laptop has not be…
- A technician is troubleshooting a laptop that shuts down randomly after a few minutes of use. The fan is spinning, and t…
Last reviewed: Jul 4, 2026
This 220-1201 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 220-1201 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.