Question 1mediummatching
Read the full MPLS explanation →Question 291 of 2,015
Quick Answer
The correct answer pairs TTL propagation with copying the IP TTL value into the MPLS TTL field, while push adds a new label to the stack, pop removes the top label, swap replaces the top label with a new one, and PHP (Penultimate Hop Popping) pops the label before the egress LER. This mapping is correct because MPLS label operations define how routers manipulate the label stack at each hop: push occurs at the ingress LER to encapsulate a packet, swap is performed by intermediate LSRs to forward traffic, pop strips the label at the egress or penultimate hop, and PHP specifically optimizes the egress LER by having the upstream router remove the label first. On the ENCOR 350-401 exam, this drag-and-drop question tests your ability to distinguish these operations in an MPLS forwarding context, often with a common trap where students confuse PHP with a standard pop—remember that PHP is a special case of pop performed by the penultimate router, not the egress. A useful memory tip is “Push to enter, Swap to travel, Pop to exit, PHP to hand off early.”
350-401 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.
Drag and drop each MPLS label operation on the left to its matching action on the right.
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
✓
Push: Adds a new label to the top of the label stack
Push adds a new label to the stack, pop removes the top label, swap replaces the top label with a new one, PHP pops the label before the egress LER, and TTL propagation copies the IP TTL into the label TTL field.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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: Push: Adds a new label to the top of the label stack — Push adds a new label to the stack, pop removes the top label, swap replaces the top label with a new one, PHP pops the label before the egress LER, and TTL propagation copies the IP TTL into the label TTL field.
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. Drag and drop each MPLS label operation on the left to its matching action on the right.
medium- ✓ P1.Push: Adds a new label to the top of the label stack
- ✓ P2.Pop: Removes the top label from the label stack
- ✓ P3.Swap: Replaces the top label with a new label value
- ✓ P4.Penultimate Hop Popping (PHP): Removes the label before the final hop
- ✓ P5.Label Imposition: Adds one or more labels to an unlabeled packet
Why P1: Push adds a new label to the stack, pop removes the top label, and swap replaces the top label with a new one.
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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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