The answer is a global routing table mismatch, where the next-hop IP addresses reside in the global table rather than within the VRF. This occurs because when subinterfaces are moved into a VRF, the CEF table for that VRF learns the destination prefixes, but the next-hop addresses must also be reachable within the same VRF context. If the next-hop addresses remain in the global routing table, the VRF has no route to them, causing the CEF entries to mark those next hops as unreachable. On the ENCOR 350-401 exam, this scenario tests your understanding of VRF route leaking and the separation of routing tables—a common trap where engineers forget that next-hop adjacencies must be established inside the VRF. A reliable memory tip is "same VRF, same next-hop": if the next hop is not in the VRF, it is unreachable.
CCNP Virtualization Practice Question
This 350-401 practice question tests your understanding of virtualization. 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.
Exhibit
Refer to the exhibit.
CEF table snippet:
Prefix Next Hop Interface
10.1.1.0/24 192.168.1.2 Ethernet0/0
10.2.2.0/24 192.168.2.2 Ethernet0/1
CEF table after VRF configuration:
VRF: TENANT_A
Prefix Next Hop Interface
10.1.1.0/24 192.168.1.2 Ethernet0/0.100
10.2.2.0/24 192.168.2.2 Ethernet0/1.200
A network engineer configured VRF TENANT_A and moved the subinterfaces into the VRF. After the change, the CEF table shows the prefixes but the next-hop addresses are unreachable. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Refer to the exhibit.
CEF table snippet:
Prefix Next Hop Interface
10.1.1.0/24 192.168.1.2 Ethernet0/0
10.2.2.0/24 192.168.2.2 Ethernet0/1
CEF table after VRF configuration:
VRF: TENANT_A
Prefix Next Hop Interface
10.1.1.0/24 192.168.1.2 Ethernet0/0.100
10.2.2.0/24 192.168.2.2 Ethernet0/1.200
A
LISP is not configured to map the virtual network.
Why wrong: Not relevant to this scenario.
B
The next-hop IP addresses are in the global routing table, not in the VRF.
Next-hops must be in the same VRF to be reachable.
C
OSPF is not redistributing the routes into the VRF.
Why wrong: Redistribution is not the issue; the next-hop is unreachable.
D
The physical interface is not configured as a trunk.
Why wrong: Subinterfaces work on access ports as well.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The next-hop IP addresses are in the global routing table, not in the VRF.
When subinterfaces are moved into a VRF, the CEF table for that VRF will contain the learned prefixes, but the next-hop addresses must also be reachable within the same VRF. If the next-hop IP addresses reside in the global routing table instead of the VRF, the VRF will have no route to those next hops, causing them to be marked as unreachable. This is a common misconfiguration where the next-hop adjacency is not established within the VRF context.
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.
✗
LISP is not configured to map the virtual network.
Why it's wrong here
Not relevant to this scenario.
✓
The next-hop IP addresses are in the global routing table, not in the VRF.
Why this is correct
Next-hops must be in the same VRF to be reachable.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
OSPF is not redistributing the routes into the VRF.
Why it's wrong here
Redistribution is not the issue; the next-hop is unreachable.
✗
The physical interface is not configured as a trunk.
Why it's wrong here
Subinterfaces work on access ports as well.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the concept that VRF creates a completely isolated routing table, and the trap here is that candidates assume CEF showing the prefix means the route is fully functional, overlooking that the next-hop must also be in the same VRF.
Trap categories for this question
Scenario analysis trap
Not relevant to this scenario.
Detailed technical explanation
How to think about this question
Under the hood, VRF creates a separate routing and forwarding table (RIB/FIB). When a route is installed in the VRF's CEF table, the next-hop resolution process checks the VRF's routing table for a connected or static route to that next-hop address. If the next-hop is only reachable via the global table, the CEF entry will show the prefix but with a 'glean' or 'unresolved' adjacency. In real-world scenarios, this often occurs when a point-to-point link's IP address is accidentally configured in the global routing table while the subinterface is in a VRF.
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.
TExam Day Tips
→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 network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Virtualization — This question tests Virtualization — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The next-hop IP addresses are in the global routing table, not in the VRF. — When subinterfaces are moved into a VRF, the CEF table for that VRF will contain the learned prefixes, but the next-hop addresses must also be reachable within the same VRF. If the next-hop IP addresses reside in the global routing table instead of the VRF, the VRF will have no route to those next hops, causing them to be marked as unreachable. This is a common misconfiguration where the next-hop adjacency is not established within the VRF context.
What should I do if I get this 350-401 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.