NSE7 Advanced Networking and SD-WAN Practice Question
An administrator sees the following output from 'get router info routing-table':
S 0.0.0.0/0 [10/0] via 192.168.1.1, port1 S 0.0.0.0/0 [10/0] via 192.168.2.1, port2
They have configured ECMP load balancing. However, traffic to a specific destination IP is always using port1. What is the likely reason?
⚠ Common exam trap
Watch out — candidates often confuse per-packet load balancing (which would alternate packets within a single flow) with FortiGate's default per-session hash-based ECMP, leading them to incorrectly select Option B.
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 destination IP hash results in the same link for all sessions due to the load balancing algorithm
D is correct because FortiGate ECMP load balancing uses a hash-based algorithm (source-destination IP, port, or protocol) by default, not per-packet. When the hash of the destination IP consistently maps to the same link (port1), all sessions to that specific IP will use that interface, even though multiple routes exist with equal administrative distance and cost.
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 firewall policy only allows traffic on port1
Why it's wrong here
Firewall policies apply to interfaces, but if both routes are present, traffic could egress either; the policy doesn't force the route.
- ✗
ECMP uses per-packet load balancing by default and the traffic is a single flow
Why it's wrong here
FortiGate uses per-flow load balancing by default, not per-packet, so a single flow uses one link.
- ✗
One of the static routes has a lower administrative distance
Why it's wrong here
Both routes have the same AD of 10.
- ✓
The destination IP hash results in the same link for all sessions due to the load balancing algorithm
Why this is correct
FortiGate's ECMP uses a hash of source/dest IP and port. If only one flow exists, it will consistently use the same link.
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.