Question 1mediummatching
Study the full AAA explanation →Question 759 of 2,015
Quick Answer
The correct mapping is REJECT to "Indicates authentication failure," as this packet type is the definitive TACACS+ response when the server denies access after evaluating credentials. This is because TACACS+ uses a three-packet exchange—START, REPLY, and CONTINUE—to separate authentication into discrete phases: START begins the session and transmits the username, REPLY sends either a challenge or a final result, and CONTINUE carries the user’s response to that challenge. On the ENCOR 350-401 exam, you must distinguish these from ACCEPT (success) and REJECT (failure), often in a drag-and-drop format that tests your recall of each packet’s role. A common trap is confusing REJECT with a CONTINUE packet that follows a failed challenge; remember that REJECT is always the terminal denial. For a quick memory tip, think of the acronym “S-R-C-A-R” (Start, Reply, Continue, Accept, Reject) and note that only REJECT and ACCEPT are final verdicts, while the others are part of the ongoing dialogue.
CCNP AAA, RADIUS, and TACACS+ Practice Question
This 350-401 practice question tests your understanding of aaa, radius, and tacacs+. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 each TACACS+ packet type on the left to its matching function on the right.
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
✓
START: Initiates an authentication session and contains the username
START begins authentication and contains username; REPLY sends challenge or result; CONTINUE sends response to challenge; ACCEPT indicates successful authentication; REJECT indicates authentication failure.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
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 350-401 questions on access control and AAA configuration.
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FAQ
Questions learners often ask
What does this 350-401 question test?
AAA, RADIUS, and TACACS+ — This question tests AAA, RADIUS, and TACACS+ — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: START: Initiates an authentication session and contains the username — START begins authentication and contains username; REPLY sends challenge or result; CONTINUE sends response to challenge; ACCEPT indicates successful authentication; REJECT indicates authentication failure.
What should I do if I get this 350-401 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 350-401 questions on access control and AAA configuration.
What is the key concept behind this question?
Authentication checks who the user is.
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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 →
Same concept, more angles
1 more ways this is tested on 350-401
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Drag and drop each TACACS+ packet type on the left to its correct function on the right.
medium- ✓ P1.START: Initiates an authentication session from the client to the server
- ✓ P2.REPLY: Sent by the server to the client, carrying prompts or authentication results
- ✓ P3.CONTINUE: Sent by the client to the server with the user's response to a prompt
- ✓ P4.AUTHOR: Used for authorization requests and responses
- ✓ P5.ACCT: Used for accounting start, stop, and interim records
Why P1: TACACS+ uses START to initiate authentication, REPLY to respond with prompts or success/failure, CONTINUE to send user responses, and also has special types for authorization and accounting.
Last reviewed: Jun 18, 2026
This 350-401 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 350-401 exam.
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