- A
Enter privileged EXEC mode using the 'enable' command.
This is correct because troubleshooting begins in privileged EXEC mode, which provides access to all necessary show and configure commands.
- B
Use the 'show interfaces' command to check for CRC errors and duplex mismatch.
This step allows you to gather diagnostic information about the interface's errors and duplex status, which is essential before making configuration changes.
- C
Configure the interface with the 'duplex full' command to fix the mismatch.
After identifying the mismatch, applying the correct duplex setting resolves the issue.
- D
Enter global configuration mode using the 'configure terminal' command.
Configuration changes require entering global configuration mode before accessing the specific interface.
CCNA Network Infrastructure and Connectivity Practice Question
This 200-301 practice question tests your understanding of network infrastructure and 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.
Drag and drop the following steps into the correct order to troubleshoot a suspected duplex mismatch and CRC errors on a Cisco switch interface.
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
Enter privileged EXEC mode using the 'enable' command.
Troubleshooting starts from privileged EXEC, checking errors, identifying the problematic interface, then configuring the correct duplex setting.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Enter privileged EXEC mode using the 'enable' command.
Why this is correct
This is correct because troubleshooting begins in privileged EXEC mode, which provides access to all necessary show and configure commands.
Related concept
Authentication checks who the user is.
- ✓
Use the 'show interfaces' command to check for CRC errors and duplex mismatch.
Why this is correct
This step allows you to gather diagnostic information about the interface's errors and duplex status, which is essential before making configuration changes.
Related concept
Authentication checks who the user is.
- ✓
Configure the interface with the 'duplex full' command to fix the mismatch.
Why this is correct
After identifying the mismatch, applying the correct duplex setting resolves the issue.
Related concept
Authentication checks who the user is.
- ✓
Enter global configuration mode using the 'configure terminal' command.
Why this is correct
Configuration changes require entering global configuration mode before accessing the specific interface.
Related concept
Authentication checks who the user is.
Common exam traps
Common exam trap: authentication is not authorization
Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.
Detailed technical explanation
How to think about this question
This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.
KKey Concepts to Remember
- Authentication checks who the user is.
- Authorization controls what the user is allowed to do after login.
- Privilege levels affect access to EXEC and configuration commands.
- AAA, TACACS+ and RADIUS can separate login success from command access.
TExam Day Tips
- Do not assume successful login means full administrative access.
- Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
- Separate login problems from permission problems before choosing the answer.
Key takeaway
Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
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.
What to study next
Got this wrong? Here's your next step.
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 200-301 questions on access control and AAA configuration.
- →
Network Infrastructure and Connectivity — study guide chapter
Learn the concepts, then practise the questions
- →
Network Infrastructure and Connectivity practice questions
Targeted practice on this topic area only
- →
All 200-301 questions
1,819 questions across all exam domains
- →
CCNA 200-301 v2 study guide
Full concept coverage aligned to exam objectives
- →
200-301 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Infrastructure and Connectivity practice questions
Practise 200-301 questions linked to Network Infrastructure and Connectivity.
Switching and Network Access practice questions
Practise 200-301 questions linked to Switching and Network Access.
IP Routing practice questions
Practise 200-301 questions linked to IP Routing.
Network Services and Security practice questions
Practise 200-301 questions linked to Network Services and Security.
AI and Network Operations practice questions
Practise 200-301 questions linked to AI and Network Operations.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
Practice this exam
Start a free 200-301 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 200-301 question test?
Network Infrastructure and Connectivity — This question tests Network Infrastructure and Connectivity — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: Enter privileged EXEC mode using the 'enable' command. — Troubleshooting starts from privileged EXEC, checking errors, identifying the problematic interface, then configuring the correct duplex setting.
What should I do if I get this 200-301 question wrong?
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 200-301 questions on access control and AAA configuration.
What is the key concept behind this question?
Authentication checks who the user is.
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 200-301 practice questions
- A switchport connected to another switch should carry multiple VLANs, but it was manually configured as an access port.…
- What problem is HSRP designed to solve?
- Which TWO statements correctly describe the causes or implications of CRC errors, runts, giants, or output errors as see…
- You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces and verify reachability to R2. The curren…
- Which TWO statements accurately describe how AI/ML concepts are applied to network operations in modern enterprise netwo…
- Which TWO switch port configurations are required when connecting a Cisco IP phone and a desktop PC to a single access p…
Last reviewed: Jun 6, 2026
This 200-301 practice question is part of Courseiva's free Cisco 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 200-301 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.