350-501 Networking Practice Question
An ISP is designing an MPLS core network and needs to choose an IGP that supports fast convergence. Which IGP meets this requirement and is most commonly used in MPLS core networks?
⚠ Common exam trap
Cisco often tests the misconception that OSPF is the default IGP for all networks, but in MPLS core environments, IS-IS is the preferred choice due to its native TE support and hierarchical scalability, making OSPF a distractor despite its fast convergence capabilities.
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
✓
IS-IS
IS-IS is the correct choice because it is a link-state IGP that inherently supports fast convergence through mechanisms like incremental SPF (iSPF) and prefix-independent convergence (PIC). It is widely deployed in MPLS core networks due to its scalability, extensibility via TLVs, and native support for MPLS Traffic Engineering (MPLS-TE) without requiring additional protocol extensions like OSPF's opaque LSA.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
IS-IS
Why this is correct
IS-IS provides fast convergence and is the predominant IGP in service provider MPLS cores.
- ✗
OSPFv3
Why it's wrong here
OSPFv3 is used for IPv6, but IS-IS is more common in MPLS cores.
- ✗
EIGRP
Why it's wrong here
EIGRP is proprietary to Cisco and not suitable for multi-vendor MPLS cores.
- ✗
RIPng
Why it's wrong here
RIPng has slow convergence and is not suitable for MPLS core.
Visual reference
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.