CGRC Control Implementation Practice Question
When implementing an 802.1X environment, what is the role of the RADIUS server?
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
✓
Authenticating the supplicant
The RADIUS server acts as the Authentication Server, validating the credentials provided by the supplicant via the authenticator.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Encapsulating EAP frames
Why it's wrong here
The switch encapsulates EAP frames into RADIUS packets (EAPoUDP).
- ✗
Providing the EAP method to the client
Why it's wrong here
The EAP method is negotiated, but the RADIUS server is the backend authority.
- ✗
Enforcing the physical port state
Why it's wrong here
The switch (authenticator) enforces the port state based on RADIUS feedback.
- ✓
Authenticating the supplicant
Why this is correct
The RADIUS server makes the final decision on access based on the credentials.
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.
About these practice questions
Courseiva writes every CGRC question from scratch — 199 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official (ISC)² exam blueprint
This CGRC practice question is part of Courseiva's free (ISC)² 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 CGRC exam.