350-601 Security Practice Question
An organization is deploying Cisco ISE for 802.1X authentication on Cisco Nexus switches. Some endpoints fail authentication and fall back to the MAB. The security policy requires that endpoints failing both 802.1X and MAB be placed in a restricted VLAN. Which configuration is needed on the switch port?
⚠ Common exam trap
It's easy for candidates to confuse 'authentication failed action' (which handles authentication failure) with 'authentication event server dead action' (which handles server unavailability), leading candidates to pick Option D when the scenario explicitly describes endpoints failing authentication, not a server outage.
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
✓
authentication failed action authorize vlan 999
The 'authentication failed action authorize vlan 999' command configures the switch port to place endpoints that fail both 802.1X and MAB into a restricted VLAN (VLAN 999). This directly meets the security policy requirement for endpoints that cannot authenticate via either method.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
authentication order dot1x mab
Why it's wrong here
This sets the order of methods, not the failure action.
- ✗
dot1x timeout tx-period 30
Why it's wrong here
This sets the retransmission timer, not the failure action.
- ✓
authentication failed action authorize vlan 999
Why this is correct
This command places the port into the specified VLAN (restricted) after authentication failure.
- ✗
authentication event server dead action authorize vlan 999
Why it's wrong here
This action is for when the server is unreachable, not for authentication failure.
Visual reference
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.
Go deeper
Related to this question
About these practice questions
This 350-601 question is part of Courseiva's 984-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-601 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 350-601 exam.