350-701 Practice Question: Secure Network Access, Visibility and Enforcement
A multinational corporation is implementing ISE for wired network access using 802.1X with EAP-TLS certificate authentication. Their Windows 10 laptops have certificates issued by an internal PKI. During testing, some users report that they are repeatedly prompted to select a certificate after connecting, and eventually authentication fails. ISE logs show 'Authentication failed - No matching certificate found'. The engineer checks the client machine and sees multiple certificates, including the correct one, in the personal store. The ISE endpoint identity store is populated with the user's AD credentials. What is the most likely cause of this failure?
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 client certificates lack the 'Client Authentication' extended key usage (EKU)
EAP-TLS requires the client to present a certificate that ISE can validate. If the client has multiple certificates and ISE receives one that does not contain the 'Client Authentication' extended key usage (EKU), ISE will reject it, logging 'No matching certificate found'. The correct answer is D because the client certificates must have the EKU for client authentication; otherwise, even if the certificates are trusted and valid, ISE will not accept them for 802.1X. Option A (expired certificate) would cause a different error. Option B (registry modification) is not standard for Windows 10 supplicant. Option C (missing trusted CA) would cause ISE to not trust any client certificate, affecting all users, not just some.
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 client's certificate is expired
Why it's wrong here
Expired certificate would be rejected with a different reason.
- ✗
The Windows supplicant requires a registry modification to enable auto-selection
Why it's wrong here
While this could cause prompt, the ultimate failure reason would still be certificate mismatch.
- ✗
ISE trusted CA certificate list does not include the issuing CA
Why it's wrong here
If the CA was not trusted, ISE would refuse all certificates from that CA, not just some.
- ✓
The client certificates lack the 'Client Authentication' extended key usage (EKU)
Why this is correct
EAP-TLS requires a certificate with Client Authentication EKU; if missing, ISE will not accept it.
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 350-701 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 350-701 exam.