Quick Answer
The answer is the `show mpls ldp neighbor` command. This is the correct choice because it directly displays the status of LDP sessions, including the neighbor’s IP address, the session state (such as “Operational”), and whether labels are being exchanged, which is exactly what an engineer needs to verify that the LDP session between two routers is up and actively distributing labels. On the Cisco SPCOR / CCNP Service Provider Core 350-501 exam, this question tests your ability to differentiate between LDP verification commands and common traps like `show mpls ldp discovery` (which only shows hello adjacency, not the full session) or `show mpls forwarding-table` (which shows label bindings but not session state). A strong memory tip is to think of “neighbor” as the session-level relationship—if you need to confirm the session is operational and exchanging labels, always look for the neighbor command.
This 350-501 practice question tests your understanding of mpls and segment routing. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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.
An MPLS core network uses LDP to distribute labels. An engineer wants to verify that the LDP session between two routers is up and exchanging labels. Which command should be used?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "which command"
Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
show mpls interfaces
Why wrong: Shows interfaces with MPLS enabled, not session state.
show mpls l2transport binding
Why wrong: Used for L2VPN.
show mpls ldp neighbor
Displays LDP neighbors and session state.
show mpls forwarding-table
Why wrong: This shows label forwarding entries, not LDP session status.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
show mpls ldp neighbor
The command 'show mpls ldp neighbor' displays the status of LDP sessions, including the neighbor's IP address, session state (e.g., Operational), and label exchange activity. Since LDP is the protocol used to distribute labels in this MPLS core network, this command directly verifies that the session is up and exchanging labels between the two routers.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
show mpls interfaces
Why it's wrong here
Shows interfaces with MPLS enabled, not session state.
show mpls l2transport binding
Why it's wrong here
Used for L2VPN.
show mpls ldp neighbor
Why this is correct
Displays LDP neighbors and session state.
Clue confirmation
The clue word "which command" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
show mpls forwarding-table
Why it's wrong here
This shows label forwarding entries, not LDP session status.
Common exam traps
Cisco often tests the distinction between verifying the LDP session itself (show mpls ldp neighbor) versus verifying the results of label exchange (show mpls forwarding-table), leading candidates to confuse the output of label distribution with the state of the label distribution protocol.
Trap categories for this question
Command / output trap
Shows interfaces with MPLS enabled, not session state.
Detailed technical explanation
LDP uses TCP port 646 for session establishment and Hello messages (UDP port 646) for neighbor discovery. The 'show mpls ldp neighbor' command reveals the LDP ID, session hold time, and whether the session is in 'Operational' state, which confirms that label exchange (via Label Mapping messages) is occurring. In real-world scenarios, a session stuck in 'Initial' or 'OpenRec' state often indicates a TCP connectivity issue or mismatched LDP parameters (e.g., transport address).
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
MPLS and Segment Routing — study guide chapter
Learn the concepts, then practise the questions
MPLS and Segment Routing practice questions
Targeted practice on this topic area only
All 350-501 questions
500 questions across all exam domains
Cisco SPCOR / CCNP Service Provider Core 350-501 study guide
Full concept coverage aligned to exam objectives
350-501 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise 350-501 questions linked to Architecture.
Practise 350-501 questions linked to Networking.
Practise 350-501 questions linked to MPLS and Segment Routing.
Practise 350-501 questions linked to Automation and Quality of Service.
Practise 350-501 questions linked to Services.
Practise 350-501 questions linked to Automation and Assurance.
Practise 350-501 questions linked to 350-501 fundamentals.
Practise 350-501 questions linked to 350-501 scenario.
Practise 350-501 questions linked to 350-501 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
MPLS and Segment Routing — This question tests MPLS and Segment Routing — Read the scenario before looking for a memorised answer..
The correct answer is: show mpls ldp neighbor — The command 'show mpls ldp neighbor' displays the status of LDP sessions, including the neighbor's IP address, session state (e.g., Operational), and label exchange activity. Since LDP is the protocol used to distribute labels in this MPLS core network, this command directly verifies that the session is up and exchanging labels between the two routers.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
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 →
Last reviewed: Jun 25, 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.
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.