hardMultiple ChoiceObjective-mapped
300-410 Practice Question: An engineer configures a Cisco router with 'aaa…
An engineer configures a Cisco router with 'aaa authentication login default group radius local' and 'aaa authentication enable default group radius enable'. The engineer then attempts to enter enable mode and is prompted for a password. The RADIUS server is reachable, but the enable password is not accepted. What is the most likely cause?
⚠ Common exam trap
Cisco often tests the distinction between the 'local' method (which uses the local username/password database) and the 'enable' method (which uses the enable password/secret), leading candidates to incorrectly assume that 'local' is needed as a fallback for enable authentication.
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 local enable password is not configured.
The 'aaa authentication enable default group radius enable' command tells the router to first contact the RADIUS server for enable authentication, and if that fails, fall back to the 'enable' method (which uses the local enable password). Since the RADIUS server is reachable, the router will attempt RADIUS authentication first. If the RADIUS server does not return a successful authentication (e.g., because it is not configured to provide the enable password), the router falls back to the 'enable' method, which requires a locally configured enable password. If no local enable password is set (via 'enable password' or 'enable secret'), the fallback fails, and the user is denied access. Therefore, the most likely cause is that the local enable password is not configured.
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 local enable password is not configured.
Why this is correct
Correct because the enable authentication method list includes 'enable' as a fallback; if no local enable password is set, the fallback fails.
- ✗
The RADIUS server is not configured to provide the enable password.
Why it's wrong here
Incorrect because the RADIUS server can provide enable access via the service type; but the issue is the local fallback.
- ✗
The 'aaa authentication enable default' command is missing the 'local' keyword.
Why it's wrong here
Incorrect because the command uses 'enable' as a fallback, not 'local'.
- ✗
The router's enable secret is set to a different password.
Why it's wrong here
Incorrect because the enable secret is used for local enable authentication; if set, it would work as a fallback.
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.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 300-410 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 300-410 exam.