350-501 MPLS and Segment Routing Practice Question
Exhibit
Router# show mpls ldp neighbor
Peer LDP Ident: 10.1.1.2:0; Local LDP Ident: 10.1.1.1:0
TCP connection: 10.1.1.2.646 - 10.1.1.1.35399
State: Oper; Msgs sent/rcvd: 148/143; Downstream
Up time: 02:15:10
LDP discovery sources:
GigabitEthernet0/0/0; Src IP addr: 10.1.1.2
Addresses bound to peer LDP Ident:
10.1.1.2 10.2.2.2
Peer LDP Ident: 10.2.2.2:0; Local LDP Ident: 10.1.1.1:0
TCP connection: 10.2.2.2.646 - 10.1.1.1.49201
State: Oper; Msgs sent/rcvd: 73/67; Downstream
Up time: 01:10:45
LDP discovery sources:
GigabitEthernet0/0/1; Src IP addr: 10.2.2.2
Addresses bound to peer LDP Ident:
10.2.2.2 10.3.3.3
Peer LDP Ident: 10.3.3.3:0; Local LDP Ident: 10.1.1.1:0
TCP connection: 10.3.3.3.646 - 10.1.1.1.52001
State: Oper; Msgs sent/rcvd: 53/49; Downstream
Up time: 00:45:30
LDP discovery sources:
GigabitEthernet0/0/2; Src IP addr: 10.3.3.3
Addresses bound to peer LDP Ident:
10.3.3.3 10.4.4.4Refer to the exhibit. The router has three LDP neighbors established. A network administrator notices that MPLS labels for the prefix 10.4.4.0/24 are not being advertised from this router to its neighbors, although the prefix is present in the routing table. Which is the most likely cause?
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 route to 10.4.4.0/24 is not the best path in the routing table.
The LDP neighbor for 10.4.4.4 (via 10.3.3.3) is up, but the router does not have a label for 10.4.4.0/24. This suggests the route is not being used for forwarding because of the IGP metric or administrative distance. Option A is wrong because the neighbor is up. Option C is wrong because LDP has been configured globally. Option D is wrong because there is no indication of an mroute issue.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The LDP session to 10.3.3.3 is down.
Why it's wrong here
The session is in Oper state, so it is up.
- ✓
The route to 10.4.4.0/24 is not the best path in the routing table.
Why this is correct
LDP assigns a label only to the best IGP route; if the route is not best, no label is allocated.
- ✗
The 'mpls ldp' command has not been applied globally.
Why it's wrong here
LDP peers are established, so it must be configured globally.
- ✗
The multicast routing table is empty for the prefix.
Why it's wrong here
Multicast routing is unrelated to LDP label distribution.
Go deeper
Related to this question
About these practice questions
This 350-501 question is part of Courseiva's 971-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.