- A
PE routers maintain separate VRF instances for each customer.
Correct because VRFs isolate customer routing tables on the PE.
- B
Route distinguishers (RDs) are used to make overlapping customer prefixes unique.
Correct because RDs prepend a 64-bit value to create unique VPNv4 prefixes.
- C
Route targets (RTs) control the import and export of routes between VRFs.
Correct because RTs are BGP extended communities that govern route distribution.
- D
P routers must maintain customer VPN routing information.
Why wrong: Incorrect because P routers only switch MPLS labels and do not need customer routes.
- E
MPLS VPNs use a single label to forward packets across the service provider core.
Why wrong: Incorrect because MPLS VPNs use two labels: an outer transport label and an inner VPN label.
Quick Answer
The answer is that route targets (RTs) control the import and export of routes between VRFs, which is a foundational truth for MPLS L3VPN. This is correct because in an MPLS Layer 3 VPN, Provider Edge (PE) routers maintain separate VRF instances for each customer, and while route distinguishers (RDs) make overlapping customer prefixes globally unique, it is the RTs that actually govern which routes are shared between VRFs and which are kept isolated. On the ENCOR 350-401 exam, this concept tests your understanding of the control plane separation in MPLS VPNs, often appearing in a "choose three" format where common traps include assuming P routers maintain customer routes or that only one MPLS label is used. Remember that P routers are label-switching only and never see the customer IP routes. A solid memory tip: think of the RD as the "ID card" making each prefix unique, and the RT as the "invitation list" controlling who gets to see it.
CCNP MPLS Practice Question
This 350-401 practice question tests your understanding of mpls. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 three statements about MPLS VPN (Layer 3 VPN) are true? (Choose three.)
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
PE routers maintain separate VRF instances for each customer.
In MPLS Layer 3 VPNs, the PE routers maintain separate VRF instances for each customer. Route distinguishers (RDs) make overlapping customer prefixes unique, while route targets (RTs) control the import/export of routes between VRFs. The P (provider) routers do not need to know about customer routes; they only switch based on MPLS labels. Option D is incorrect because P routers do not maintain customer routes. Option E is incorrect because MPLS VPNs use two labels: the inner label identifies the egress PE, and the outer label is used for transport through the core.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
PE routers maintain separate VRF instances for each customer.
Why this is correct
Correct because VRFs isolate customer routing tables on the PE.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Route distinguishers (RDs) are used to make overlapping customer prefixes unique.
Why this is correct
Correct because RDs prepend a 64-bit value to create unique VPNv4 prefixes.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Route targets (RTs) control the import and export of routes between VRFs.
Why this is correct
Correct because RTs are BGP extended communities that govern route distribution.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
P routers must maintain customer VPN routing information.
Why it's wrong here
Incorrect because P routers only switch MPLS labels and do not need customer routes.
- ✗
MPLS VPNs use a single label to forward packets across the service provider core.
Why it's wrong here
Incorrect because MPLS VPNs use two labels: an outer transport label and an inner VPN label.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 350-401 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. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. 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.
Identify which 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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FAQ
Questions learners often ask
What does this 350-401 question test?
MPLS — This question tests MPLS — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: PE routers maintain separate VRF instances for each customer. — In MPLS Layer 3 VPNs, the PE routers maintain separate VRF instances for each customer. Route distinguishers (RDs) make overlapping customer prefixes unique, while route targets (RTs) control the import/export of routes between VRFs. The P (provider) routers do not need to know about customer routes; they only switch based on MPLS labels. Option D is incorrect because P routers do not maintain customer routes. Option E is incorrect because MPLS VPNs use two labels: the inner label identifies the egress PE, and the outer label is used for transport through the core.
What should I do if I get this 350-401 question wrong?
Identify which 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more ways this is tested on 350-401
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which two statements about MPLS VPN (Layer 3 VPN) are true? (Choose two.)
medium- ✓ A.PE routers maintain separate VRF tables for each VPN customer.
- B.P routers must maintain a full routing table for each VPN customer.
- ✓ C.MP-BGP is used to exchange VPNv4 routes between PE routers.
- D.CE routers run MPLS and participate in label distribution with the PE.
- E.The VPN label is used by P routers to forward traffic across the MPLS core.
Why A: In MPLS Layer 3 VPNs, the PE router maintains separate VRF tables per customer and uses MP-BGP to exchange VPNv4 routes (including the route distinguisher and VPN label). The P router does not need to know customer routes; it only swaps labels. The CE router does not participate in MPLS; it runs standard IP routing with the PE.
Last reviewed: Jun 18, 2026
This 350-401 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 350-401 exam.
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