SD-WAN Sessions Load Balancing Algorithm
Which SD-WAN load balancing algorithm distributes traffic based on the number of active sessions per SD-WAN member?
Quick Answer
The answer is the Sessions algorithm. This SD-WAN load balancing algorithm distributes traffic based on the number of active sessions per SD-WAN member, meaning the member with the fewest current sessions receives the next new connection. It is correct because it focuses purely on session count as the metric, unlike other algorithms that consider bandwidth, latency, or volume. On the Fortinet NSE 7 Advanced Security NSE7 exam, this tests your understanding of how SD-WAN load balancing methods differ in their decision logic; a common trap is confusing Sessions with the Volume algorithm, which tracks bytes transferred rather than connection count. To remember, think of a bank teller line: the Sessions algorithm sends the next customer to the teller with the shortest line, regardless of how complex each customer’s transaction might be.
⚠ Common exam trap
Watch out — candidates often confuse 'Sessions' with 'Volume' or 'Spillover', assuming traffic distribution is always based on bandwidth usage rather than session count, which is a distinct metric in Fortinet SD-WAN load balancing.
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
✓
Sessions
The Sessions algorithm in Fortinet SD-WAN distributes traffic by counting the number of active sessions currently traversing each SD-WAN member interface. The member with the fewest active sessions receives the next new session, ensuring a balanced session load across the SD-WAN links. This is distinct from volume-based or hash-based algorithms, as it directly uses session count as the metric.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Sessions
Why this is correct
Sessions balances by number of active sessions.
- ✗
Source-dest-IP
Why it's wrong here
Source-dest-IP hashes based on source/destination IP.
- ✗
Spillover
Why it's wrong here
Spillover sends excess traffic to another member.
- ✗
Volume
Why it's wrong here
Volume uses traffic volume, not session count.
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Same concept, more angles
3 more ways this is tested on NSE7
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which SD-WAN load balancing algorithm distributes new sessions based on the number of active sessions on each link?
easy- A.Source-dest IP
- B.Spillover
- C.Volume
- ✓ D.Sessions
Why D: The Sessions algorithm distributes new sessions based on the current number of active sessions on each SD-WAN link. When a new session is initiated, the SD-WAN controller selects the link with the fewest active sessions, ensuring a balanced load across all available transport interfaces. This is distinct from algorithms that consider source/destination IP pairs, traffic volume, or bandwidth thresholds.
Variation 2. Which SD-WAN load balancing algorithm distributes traffic based on the number of active sessions per interface?
easy- ✓ A.Sessions
- B.Volume
- C.Source-destination IP
- D.Spillover
Why A: The Sessions algorithm in Fortinet SD-WAN distributes new sessions by selecting the interface with the fewest currently active sessions. This ensures balanced session distribution across WAN links, preventing any single interface from becoming overloaded with connections while others remain underutilized.
Variation 3. Which load balancing algorithm in SD-WAN sends new sessions to the member interface with the least number of active sessions?
easy- ✓ A.Sessions
- B.Volume
- C.Spillover
- D.Source-dest IP
Why A: The Sessions algorithm in Fortinet SD-WAN selects the member interface with the fewest active sessions when a new session is initiated. This is the default load-balancing method and ensures even distribution of session counts across WAN links, preventing any single interface from becoming overloaded with connections.
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.