- A
Configuration changes take effect immediately without commit
Why wrong: IOS XR requires commit.
- B
Commit/rollback configuration model
Changes are staged and committed.
- C
Monolithic kernel where all processes share memory
Why wrong: IOS XR uses process separation.
- D
Distributed OS with process separation
Each protocol runs as a separate process.
- E
All line cards run a single control plane process
Why wrong: Control plane can be distributed.
Question 661 of 1,000
350-501 Architecture Practice Question
This 350-501 practice question tests your understanding of architecture. 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.
Which TWO of the following are characteristics of the IOS XR operating system architecture? (Select two.)
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
✓
Commit/rollback configuration model
IOS XR features a distributed OS and a commit/rollback configuration model.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Configuration changes take effect immediately without commit
Why it's wrong here
IOS XR requires commit.
- ✓
Commit/rollback configuration model
Why this is correct
Changes are staged and committed.
Related concept
Authentication checks who the user is.
- ✗
Monolithic kernel where all processes share memory
Why it's wrong here
IOS XR uses process separation.
- ✓
Distributed OS with process separation
Why this is correct
Each protocol runs as a separate process.
Related concept
Authentication checks who the user is.
- ✗
All line cards run a single control plane process
Why it's wrong here
Control plane can be distributed.
Common exam traps
Common exam trap: authentication is not authorization
Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.
Detailed technical explanation
How to think about this question
This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.
KKey Concepts to Remember
- Authentication checks who the user is.
- Authorization controls what the user is allowed to do after login.
- Privilege levels affect access to EXEC and configuration commands.
- AAA, TACACS+ and RADIUS can separate login success from command access.
TExam Day Tips
- Do not assume successful login means full administrative access.
- Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
- Separate login problems from permission problems before choosing the answer.
Key takeaway
Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Real-world example
How this comes up in practice
A practitioner preparing for the 350-501 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 350-501 questions on access control and AAA configuration.
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FAQ
Questions learners often ask
What does this 350-501 question test?
Architecture — This question tests Architecture — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: Commit/rollback configuration model — IOS XR features a distributed OS and a commit/rollback configuration model.
What should I do if I get this 350-501 question wrong?
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 350-501 questions on access control and AAA configuration.
What is the key concept behind this question?
Authentication checks who the user is.
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Last reviewed: Jul 4, 2026
This 350-501 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 350-501 exam.
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