Networking →mediumMultiple ChoiceObjective-mapped

350-501 Networking Practice Question

Exhibit

Refer to the exhibit.

Router# show mpls ldp bindings
 tib entry: 10.0.0.0/8, rev 4
        local binding:  tag: 160
        remote binding: tsr: 192.168.1.1:0, tag: 160
                        tsr: 192.168.2.2:0, tag: 161
 tib entry: 10.1.1.0/24, rev 8
        local binding:  tag: 161
        remote binding: tsr: 192.168.1.1:0, tag: 162
                        tsr: 192.168.2.2:0, tag: imp-null

Based on the exhibit, which statement about label allocation for prefix 10.1.1.0/24 is true?

⚠ Common exam trap

Cisco often tests the distinction between label allocation (which router assigns the label) and PHP (which router pops the label), causing candidates to confuse the ingress LSR's role with that of the penultimate hop.

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

✓

The local router allocated label 161 for the prefix

The exhibit shows that the local router (192.168.1.2) has allocated label 161 for prefix 10.1.1.0/24, as indicated in the output of the 'show mpls forwarding-table' command. This label is assigned by the local router as the ingress LSR to forward traffic toward the egress LSR (192.168.1.1). The correct statement is that the local router allocated label 161 for this prefix.

Answer analysis

Option-by-option breakdown

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

✗
Router 192.168.2.2 is the penultimate hop for this prefix.
Why it's wrong here
Penultimate hop would push label; imp-null means it wants PHP.
✗
The local router will use PHP for this prefix.
Why it's wrong here
Local router receives imp-null from 192.168.2.2, so it may pop label, but that is not PHP (PHP is done by penultimate hop).
✓
The local router allocated label 161 for the prefix
Why this is correct
Yes, local binding tag is 161.
✗
Router 192.168.1.1 is the egress LSR for this prefix.
Why it's wrong here
192.168.2.2 is likely egress because it uses imp-null.

Go deeper

350-501 Networking Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

Related to this question