TACACS+ is the correct choice because it provides granular per-command authorization and encrypts the entire session, including all command traffic and credentials. Unlike RADIUS, which only encrypts the password and lacks per-command control, TACACS+ separates authentication, authorization, and accounting (AAA) functions, allowing administrators to define exactly which commands each user can execute on routers and switches. On the CompTIA Network+ N10-009 exam, this distinction is frequently tested in scenario-based questions where an organization needs strict command-level control and full session encryption—a common trap is choosing RADIUS because it is more familiar for network access, but remember that RADIUS is designed for port-based access (like VPNs or Wi-Fi), not device administration. A useful memory tip: TACACS+ is for “terminal access control” (think Telnet/SSH to devices), while RADIUS is for “remote access” (think connecting users to the network).
N10-009 Network Security Practice Question
This N10-009 practice question tests your understanding of network security. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
An organization needs to authenticate network administrators and control which commands each administrator can execute on routers and switches. The solution must support granular per-command authorization and encrypt the entire session. Which protocol is best suited for this requirement?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Correct. TACACS+ encrypts the entire session and supports granular command authorization for device administration.
B
RADIUS
Why wrong: RADIUS is primarily used for network access authentication (e.g., 802.1X, VPN) and does not provide command-level authorization for device administration.
C
LDAP
Why wrong: LDAP is used for querying directory services (e.g., user attributes) and does not provide AAA for network devices.
D
Kerberos
Why wrong: Kerberos provides authentication via tickets but not per-command authorization; it is not typically used for device administration.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
TACACS+
TACACS+ is the correct choice because it separates authentication, authorization, and accounting (AAA) functions, allowing granular per-command authorization on routers and switches. It encrypts the entire session, including the username, password, and all command traffic, unlike RADIUS which only encrypts the password. This makes TACACS+ ideal for environments requiring strict command-level control and full session encryption.
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.
✓
TACACS+
Why this is correct
Correct. TACACS+ encrypts the entire session and supports granular command authorization for device administration.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
RADIUS
Why it's wrong here
RADIUS is primarily used for network access authentication (e.g., 802.1X, VPN) and does not provide command-level authorization for device administration.
✗
LDAP
Why it's wrong here
LDAP is used for querying directory services (e.g., user attributes) and does not provide AAA for network devices.
✗
Kerberos
Why it's wrong here
Kerberos provides authentication via tickets but not per-command authorization; it is not typically used for device administration.
Common exam traps
Common exam trap: answer the scenario, not the keyword
CompTIA often tests the distinction that RADIUS is commonly used for network access control (e.g., 802.1X) but fails for device administration because it lacks per-command authorization and full-session encryption, leading candidates to mistakenly choose RADIUS due to its familiarity.
Trap categories for this question
Command / output trap
RADIUS is primarily used for network access authentication (e.g., 802.1X, VPN) and does not provide command-level authorization for device administration.
Detailed technical explanation
How to think about this question
TACACS+ uses TCP port 49 and encrypts the entire payload (authentication, authorization, and accounting packets) using a shared secret key, ensuring no cleartext data is transmitted. For per-command authorization, TACACS+ sends each command to the AAA server, which checks against a configured privilege level or command set (e.g., via 'authorization commands 15' in Cisco IOS), allowing or denying execution in real time. In contrast, RADIUS uses UDP (ports 1812/1813) and only encrypts the password field, making it unsuitable for environments where command-level auditing and encryption are required.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
Network Security — This question tests Network Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: TACACS+ — TACACS+ is the correct choice because it separates authentication, authorization, and accounting (AAA) functions, allowing granular per-command authorization on routers and switches. It encrypts the entire session, including the username, password, and all command traffic, unlike RADIUS which only encrypts the password. This makes TACACS+ ideal for environments requiring strict command-level control and full session encryption.
What should I do if I get this N10-009 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: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 →
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.
This N10-009 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 N10-009 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.