300-410 Infrastructure Services Practice Question
A network administrator is configuring a Cisco IOS XE router to support MPLS L3VPN. The administrator needs to enable MPLS forwarding on an interface that connects to the service provider core. Which command should be applied to the interface?
⚠ Common exam trap
The trap here is selecting 'tag-switching ip' as an alternative to 'mpls ip'; while functionally similar, it is deprecated and not the correct command for current Cisco IOS XE.
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
✓
mpls ip
The 'mpls ip' command is the standard way to enable MPLS forwarding on an interface in Cisco IOS XE. It allows the interface to forward labeled packets, which is required for MPLS L3VPN. The other commands either set global parameters or use deprecated syntax, and do not directly enable MPLS forwarding on the interface.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
tag-switching ip
Why it's wrong here
The 'tag-switching ip' command is an older syntax used in Cisco IOS for enabling MPLS forwarding, equivalent to 'mpls ip'. However, in modern Cisco IOS XE, the correct command is 'mpls ip'. Using 'tag-switching ip' may not be supported or could be deprecated, so it is not the best choice for current deployments.
- ✓
mpls ip
Why this is correct
The 'mpls ip' command enables MPLS forwarding on the interface, allowing it to send and receive labeled packets. This is essential for the interface to participate in the MPLS core. It is the correct command to enable MPLS on a core-facing interface in an MPLS L3VPN deployment.
- ✗
mpls label protocol ldp
Why it's wrong here
The 'mpls label protocol ldp' command specifies LDP as the label distribution protocol on an interface, but it does not enable MPLS forwarding. It is used in conjunction with 'mpls ip' to select LDP. Without 'mpls ip', MPLS forwarding is not enabled, so this command alone is insufficient.
- ✗
mpls ldp router-id loopback0
Why it's wrong here
The 'mpls ldp router-id loopback0' command sets the LDP router ID to the loopback0 interface, but it does not enable MPLS forwarding on a specific interface. It is a global configuration command, not an interface command. While it is part of MPLS LDP configuration, it does not directly enable MPLS on the core-facing interface.
Go deeper
Related to this question
Learn chapter
Device Management and Network Monitoring (SNMP, Syslog, NetFlow)
Key term
MPLS Layer 3 VPN
A technology that uses Multiprotocol Label Switching to create secure, scalable virtual private networks that connect multiple sites at the network layer, where the service provider manages routing between customer sites.
Key term
LDP Protocol
LDP, or Label Distribution Protocol, is a protocol that routers use to automatically exchange labels that enable MPLS (Multiprotocol Label Switching) to create fast, efficient paths for data packets across a network.
About these practice questions
This 300-410 question is part of Courseiva's 1,401-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 and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 300-410 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 300-410 exam.