Courseiva
← 350-401
Full test
mediumMultiple ChoiceObjective-mapped

Interpreting show mpls ldp bindings Output

A network engineer runs the following command on Router R3:

R3# show mpls ldp bindings

lib entry: 10.1.1.1/32, rev 2 local binding: label: 16 remote binding: lsr: 10.1.1.2:0, label: 17 lib entry: 10.2.2.0/24, rev 4 local binding: label: 18 remote binding: lsr: 10.1.1.2:0, label: 19 lib entry: 10.3.3.0/24, rev 6 local binding: label: 20 remote binding: lsr: 10.1.1.2:0, label: 21

Based on this output, what is true?

Quick Answer

The correct interpretation is that for prefix 10.1.1.1/32, the local label is 16 and the remote label from LSR 10.1.1.2 is 17. This is because the show mpls ldp bindings command displays the Label Information Base (LIB), which lists every prefix learned via LDP along with two key bindings: the local label that this router (R3) has assigned, and the remote label advertised by a neighboring Label Switch Router (LSR). In the output, each "lib entry" shows a prefix, followed by its local binding and then the remote binding from a specific LSR—here, 10.1.1.2. On the ENCOR 350-401 exam, this command tests your ability to read the LIB and distinguish between locally assigned labels and labels learned from peers, a common point of confusion. A frequent trap is mixing up the local and remote labels, or assuming the "rev" number indicates label priority when it is simply a revision counter. Memory tip: think of "local" as what your router gives out, and "remote" as what your neighbor sends you—like a handshake where each side offers its own label.

⚠ Common exam trap

Cisco often tests the ability to correctly interpret 'show mpls ldp bindings' output, specifically the trap is that candidates confuse the remote label as the label the local router will use to forward traffic, when in fact the remote label is what the peer uses to reach the FEC.

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

✓

For prefix 10.1.1.1/32, the local label is 16 and the remote label from LSR 10.1.1.2 is 17.

The output of 'show mpls ldp bindings' directly shows that for prefix 10.1.1.1/32, the local label assigned by R3 is 16, and the remote label learned from LSR 10.1.1.2 (its LDP peer) is 17. This is a straightforward reading of the command output, confirming the local and remote label bindings for that FEC.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • ✓

    For prefix 10.1.1.1/32, the local label is 16 and the remote label from LSR 10.1.1.2 is 17.

    Why this is correct

    The output clearly shows local binding label 16 and remote binding label 17.

  • ✗

    The router has learned label bindings from two different LDP peers.

    Why it's wrong here

    All remote bindings are from the same LSR: 10.1.1.2:0.

  • ✗

    The label for prefix 10.2.2.0/24 is 18 locally and 19 remotely, indicating that the remote LSR will use label 18.

    Why it's wrong here

    The remote label is 19, not 18. The local label is 18.

  • ✗

    The LIB entry for 10.3.3.0/24 has a revision number of 6, meaning it was the sixth entry added.

    Why it's wrong here

    The rev number is per entry, not a global counter; it indicates the revision of that specific entry.

About these practice questions

Courseiva writes every 350-401 question from scratch — 1,175 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Same concept, more angles

1 more way 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. A network engineer runs the following command on Router R9: R9# show mpls ldp bindings 10.9.9.0 255.255.255.0 lib entry: 10.9.9.0/24, rev 10 local binding: label: 22 remote binding: lsr: 10.9.9.1:0, label: 23 remote binding: lsr: 10.9.9.2:0, label: 24 remote binding: lsr: 10.9.9.3:0, label: 25 Based on this output, how many remote LDP peers have advertised a label for the prefix 10.9.9.0/24?

easy
  • A.1
  • B.2
  • ✓ C.3
  • D.4

Why C: The output shows three remote bindings, each from a different LSR (10.9.9.1:0, 10.9.9.2:0, and 10.9.9.3:0), advertising a label for the prefix 10.9.9.0/24. The local binding (label 22) is not a remote peer, so only the three remote entries count. Therefore, the correct answer is 3.

JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

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.