NSE7 Advanced Networking and SD-WAN Practice Question
Which FortiGate feature is used to detect link failures within milliseconds, allowing rapid convergence for routing protocols like OSPF and BGP?
⚠ Common exam trap
It's easy for candidates to confuse OSPF Fast Hello (which still operates in the hundreds-of-milliseconds range) with BFD's true sub-100 ms detection, or they mistakenly think ECMP or route tagging are involved in failure detection.
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
✓
BFD
Bidirectional Forwarding Detection (BFD) is the correct answer because it provides sub-second (millisecond) link failure detection independent of routing protocols. Unlike OSPF or BGP's own keepalive mechanisms, BFD can detect failures in as little as 50-100 ms, enabling rapid convergence for protocols like OSPF and BGP by immediately notifying them of a neighbor loss.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
ECMP
Why it's wrong here
ECMP is load balancing, not failure detection.
- ✗
OSPF Fast Hello
Why it's wrong here
Fast Hello can provide sub-second detection but only for OSPF; BFD is protocol-independent.
- ✓
BFD
Why this is correct
BFD offers fast failure detection.
- ✗
Route tagging
Why it's wrong here
Route tagging is for marking routes, not link detection.
Visual reference
Go deeper
Related to this question
About these practice questions
Courseiva writes every NSE7 question from scratch — 940 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 →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This NSE7 practice question is part of Courseiva's free Fortinet 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 NSE7 exam.