300-410 Infrastructure Services Practice Question
A network engineer is deploying an MPLS Layer 3 VPN for a customer. The customer requires that the provider edge (PE) routers support a unique route distinguisher (RD) per VRF and that the same customer routes be imported into multiple VRFs. Which configuration on the PE router accomplishes this requirement?
⚠ Common exam trap
Candidates often confuse the role of the route distinguisher with that of the route target; the RD makes prefixes unique, while the RT controls import/export.
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
✓
Configure a unique RD under each VRF and use route targets (RTs) to control import and export of routes between VRFs.
A unique route distinguisher per VRF ensures that overlapping customer prefixes remain distinct in the MP-BGP VPNv4 table. Route targets, which are BGP extended communities, define import and export policies so that the same customer routes can be imported into multiple VRFs. This combination is the standard method for shared services and overlapping VPNs.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Configure a unique RD under each VRF and use route targets (RTs) to control import and export of routes between VRFs.
Why this is correct
A unique RD per VRF ensures that identical customer prefixes from different VRFs do not conflict in the MP-BGP table. Route targets then define which VRFs import or export those routes, allowing the same customer routes to be imported into multiple VRFs. This is the standard MPLS L3VPN design for overlapping address spaces and shared services.
- ✗
Configure a unique RD per VRF and use OSPF areas to import routes into multiple VRFs.
Why it's wrong here
OSPF areas are used within an IGP to control topology and summarization; they do not govern route import/export between VRFs in an MPLS L3VPN. Import/export is controlled by route targets carried in BGP extended communities. OSPF cannot achieve the required inter-VRF route sharing.
- ✗
Configure the same RD for all VRFs and rely on BGP extended communities for route distribution.
Why it's wrong here
Using the same RD for all VRFs causes identical prefixes from different VRFs to be treated as the same route in MP-BGP, leading to conflicts and incorrect forwarding. RDs must be unique per VRF to maintain separate routing tables. Extended communities alone cannot resolve the ambiguity created by duplicate RDs.
- ✗
Configure a unique RD per VRF and use BGP confederations to import routes into multiple VRFs.
Why it's wrong here
While a unique RD per VRF is correct, BGP confederations are used to reduce IBGP mesh requirements within an autonomous system; they do not control import/export of routes between VRFs. Route targets, not confederations, are the mechanism for importing routes into multiple VRFs.
Go deeper
Related to this question
Learn chapter
EIGRP Route Summarization and Filtering
Key term
MPLS Layer 3 VPN
A technology that uses Multiprotocol Label Switching to create secure, scalable virtual private networks that connect multiple sites at the network layer, where the service provider manages routing between customer sites.
Key term
LDP Protocol
LDP, or Label Distribution Protocol, is a protocol that routers use to automatically exchange labels that enable MPLS (Multiprotocol Label Switching) to create fast, efficient paths for data packets across a network.
About these practice questions
One of 1,401 original 300-410 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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 September 2026 · checked against the official Cisco exam blueprint
This 300-410 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 300-410 exam.