Session-Based Restrictions | Fortinet’s SD-WAN’s session-based solution causes downtimes during WAN issues as it cannot reliably switch paths
Key Insights on Fortinet’s SD-WAN Challenges
Session-Based Limitations: Research suggests Fortinet’s SD-WAN relies on session-based load balancing, which may lead to downtime during WAN disruptions, as sessions cannot seamlessly switch paths mid-flow.
Vulnerability Concerns: Evidence from cybersecurity advisories indicates Fortinet products face frequent exploits, potentially making them a risky choice for uptime-critical businesses.
Architecture Drawbacks: It appears Fortinet operates more like an edge-focused site-to-site VPN without built-in cloud-native resilience, doubling outage risks in hub-and-spoke setups due to unmitigated last-mile failures.
DNS and Visibility Issues: User reports highlight unreliable DNS performance and limited monitoring, which could obscure problems until they cause major disruptions.
Superior Alternatives: Solutions like packet-based SD-WAN with elastic IPs, such as those from Nepean Networks, seem to offer better failover and redundancy, addressing these gaps from packet level to higher layers.
Why Packets Matter in SD-WAN Reliability
Packets form the foundation of network traffic, and how an SD-WAN handles them can determine uptime. Session-based systems, like Fortinet’s, lock traffic to a single path per session, meaning any WAN event—such as jitter or link failure—can interrupt ongoing connections. In contrast, packet-based approaches evaluate and route each packet independently, enabling sub-second failover without dropping sessions. This is particularly beneficial for real-time applications like VoIP or video conferencing.
The Role of Elastic IPs & Cloud-Native Design
Elastic (or floating) IPs allow dynamic reassignment of public IPs across instances, ensuring continuity during failures. Fortinet lacks native elastic IP support in its SD-WAN, exacerbating downtime risks. Cloud-native solutions mitigate this by routing traffic through resilient data centers near internet peering points, reducing last-mile vulnerabilities. For hub-and-spoke (head office and branch) deployments, this centralized approach avoids outages from failures at either end, unlike edge-only architectures.
Security & Operational Risks with Fortinet
Fortinet’s infrastructure has been flagged in multiple U.S. Cybersecurity and Infrastructure Security Agency (CISA) alerts for active exploitation of vulnerabilities, raising questions about its suitability for business-critical SD-WAN. Combined with reported DNS unreliability—often described as prone to outages—and poor visibility tools that fail to provide proactive insights, these factors could lead to undetected issues escalating into full downtime.
Nepean Networks as a Resilient Alternative
Nepean Networks’ SD-WAN addresses these concerns through a packet-based, cloud-hosted design with features like bulletproof DNS for five-nines reliability, bandwidth aggregation for seamless failover, and AI-driven analytics for clear visibility. This makes it a potentially stronger option for businesses prioritizing uptime, though individual needs may vary.
Unmasking Fortinet’s SD-WAN | A Web of Single Points of Failure in a High-Stakes World
In the relentless arena of modern business networking, where every second of downtime can bleed revenue and erode trust, SD-WAN solutions promise a lifeline of seamless connectivity. But not all SD-WANs are created equal. Fortinet’s offering, while marketed as secure and efficient, is riddled with architectural flaws that expose businesses to unnecessary risks. It starts with the packets—and the packets don’t lie. Fortinet’s session-based approach, poor cloud integration, vulnerability-laden infrastructure, unreliable DNS, and foggy visibility combine to create a fragile system unfit for delivering the ironclad uptime today’s enterprises demand. Meanwhile, innovative alternatives like Nepean Networks’ packet-based, cloud-native SD-WAN rise as a beacon of resilience, systematically dismantling single points of failure (SPOFs) from the ground up.
The Packet Predicament | Session-Based Fragility vs. Packet-Based Power
At the heart of any SD-WAN is how it manages traffic. Fortinet opts for a session-based model, where entire sessions—think a video call or file transfer—are pinned to a single path. This means if a WAN event occurs, like packet loss or latency spikes, the session breaks, forcing a restart and inevitable downtime. Users on forums like Reddit have lamented this, noting that even minor disruptions lead to noticeable interruptions, making it ill-suited for mission-critical operations.
Contrast this with packet-based SD-WAN, which treats each packet independently, dynamically routing them across the best available paths in real-time. This enables sub-second failover without session drops, ensuring applications remain fluid even amid chaos. Fortinet lacks native elastic IP support—a feature that dynamically reassigns IPs to maintain connectivity during failures—further compounding the issue. Elastic IPs, common in robust cloud setups, allow traffic to float seamlessly between endpoints, slashing outage risks. Without it, Fortinet’s SD-WAN feels archaic, unable to adapt to the unpredictable nature of modern WANs.
Architectural Atrophy | Edge-Centric VPN Masquerading as SD-WAN
Fortinet’s SD-WAN is essentially a glorified site-to-site VPN, tethered to edge devices without true cloud-native DNA. Deployed in classic hub-and-spoke models—head office (HO) to branches—it doubles the peril: a last-mile failure at the HO or any branch cascades into widespread outages, with no built-in mitigation. Its virtual variants, meant for flexibility, are notoriously clunky, resource-hungry, and deployment nightmares, demanding heavy hardware and constant tweaking.
A superior blueprint? Cloud-based SD-WAN, whether public or private, funnels traffic to data centers nestled near internet peering points. Here, redundant paths abound, shielding against last-mile woes. This decentralized resilience turns potential disasters into blips, ensuring uptime in distributed environments. Fortinet’s edge obsession ignores this, leaving businesses exposed in an era where hybrid work and cloud reliance amplify connectivity demands.
Vulnerability Vortex | The Most Exploitable Infrastructure?
Don’t just take the critique at face value—turn to the experts. The U.S. CISA has repeatedly flagged Fortinet products with Known Exploited Vulnerabilities (KEVs), including zero-days actively abused by threat actors. From post-exploitation techniques in FortiGate firewalls to widespread attacks on SD-WAN components, these advisories paint a picture of an infrastructure under siege. Would you stake your business’s uptime on a platform that’s a magnet for cybercriminals? In a world where ransomware and DDoS attacks thrive on weak links, Fortinet’s track record screams caution.
DNS Debacle & Visibility Void | Blind Spots Galore
Fortinet’s DNS? Far from five-nines reliability—more like a sputtering engine prone to stalling. Community reports abound of intermittent failures, high latency, and outright downtime, forcing users to bypass it for public alternatives like Cloudflare. It’s an afterthought, no smarter than a budget router, lacking intelligence to preempt issues.
Visibility fares no better. Fortinet’s monitoring tools are criticized as opaque, like peering through smeared lenses—offering limited analytics that only reveal problems post-catastrophe. No proactive forensics mean you’re flying blind, unable to dissect pre- or post-event traffic for root causes.
Nepean Networks | The Antidote to Fortinet’s Flaws
Enter Nepean Networks, a security-agnostic, MSP-first SD-WAN that’s packet-based at its core, ensuring stable sessions even during last-mile turbulence. Launched by Fusion Broadband, it aggregates bandwidth for instant failover, preventing thousands of downtime hours monthly. Its cloud-native fabric routes traffic through resilient data centers, mitigating SPOFs with sub-second redundancy and application-aware routing.
At the packet level, deep inspection (DPI) delivers unbiased analytics, while elastic (floating) IPs maintain connectivity dynamically. DNS? Bulletproof with five-nines uptime, anti-hijacking, and filtering—no more weak links. Visibility shines via AI-driven tools like Illuminate for real-time insights and packet captures with Wireshark, empowering proactive management. Beyond basics, features like private WAN overlays and secure remote access fortify against failures, all managed through the intuitive Antares portal.
In head-to-head terms, Nepean sidesteps Fortinet’s session rigidity with packet agility, counters vulnerability risks with vendor-agnostic security, and eclipses DNS/visibility gaps with robust, intelligent tools. It’s not just SD-WAN—it’s a fortress against fragility.
| Feature Comparison | Fortinet SD-WAN | Nepean Networks SD-WAN |
| Traffic Handling | Session-based; prone to downtime on WAN events | Packet-based; sub-second failover, stable sessions |
| Architecture | Edge-focused VPN; last-mile vulnerabilities in hub-spoke | Cloud-native; data center routing near peering points |
| DNS Reliability | Frequent outages, basic functionality | Five-nines, anti-hijacking, bulletproof design |
| Visibility & Monitoring | Limited analytics; reactive insights | AI-driven DPI, real-time packet capture, proactive alerts |
| Failover & Redundancy | Session-locked; no elastic IP | Instant aggregation, elastic IPs, mitigates SPOFs |
| Vulnerability Profile | Multiple CISA KEVs; active exploits | Security-agnostic; integrates robust NGFW options |
| Deployment Ease | Clunky virtuals, resource-intensive | Fast, scalable, MSP-friendly with white-labeling |
Fortinet’s SD-WAN, for all its security claims, crumbles under scrutiny as a patchwork of SPOFs. Businesses deserve better: resilient, adaptive networks that deliver uptime without compromise. Nepean Networks exemplifies this shift, proving that true innovation lies in eliminating weaknesses, not papering over them.
Key Citations:
- SD-WAN Rule – Per session or per packet? | r/fortinet – Reddit (https://www.reddit.com/r/fortinet/comments/basuik/sdwan_rule_per_session_or_per_packet/)
- Session-Based vs. Packet-Based Load Balancing in SD-WAN (https://turnium.com/what-you-need-to-know-about-session-based-vs-packet-based-load-balancing-in-sd-wan/)
- SD-WAN line failure notification | r/fortinet – Reddit (https://www.reddit.com/r/fortinet/comments/sbr4l3/sdwan_line_failure_notification/)
- [PDF] Path-Based vs Session-Based SD-WAN | CommandLink (https://www.commandlink.com/wp-content/uploads/2024/02/Path-Based-vs-Session-Based-SD-WAN.pdf)
- 🌶️Nepean Networks’s SD-WAN | Revolutionising the Future of Networking🧨 (https://hubandspoke.amastelek.com/fusions-sd-wan-revolutionising-the-future-of-networking)
- SD-WAN designs and architectures | FortiGate / FortiOS 7.6.4 (https://docs.fortinet.com/document/fortigate/7.6.4/administration-guide/504287/sd-wan-designs-and-architectures)
- Is Your SD-WAN Deployment Doomed? Avoid These 5 Fortinet … (https://uplinqtec.com/is-your-sd-wan-deployment-doomed-avoid-these-5-fortinet-pitfalls-now/)
- FortiGate SD-WAN Pros and Cons | User Likes & Dislikes – G2 (https://www.g2.com/products/fortigate-sd-wan/reviews?qs=pros-and-cons)
- Fortinet Releases Advisory on New Post-Exploitation Technique for … (https://www.cisa.gov/news-events/alerts/2025/04/11/fortinet-releases-advisory-new-post-exploitation-technique-known-vulnerabilities)
- Fortinet Releases Security Updates for Multiple Products – CISA (https://www.cisa.gov/news-events/alerts/2025/01/14/fortinet-releases-security-updates-multiple-products)
- CISA Adds Three Known Exploited Vulnerabilities to Catalog (https://www.cisa.gov/news-events/alerts/2025/06/25/cisa-adds-three-known-exploited-vulnerabilities-catalog)
- CISA Alerts on Active Exploitation of Fortinet Zero-Day Vulnerability (https://cyberpress.org/cisa-fortinet-zero-day/)
- DNS Server Issues : r/fortinet – Reddit (https://www.reddit.com/r/fortinet/comments/1h3r99z/dns_server_issues/)
- FortiGuard DNS issue – the Fortinet Community! (https://community.fortinet.com/t5/Support-Forum/FortiGuard-DNS-issue/td-p/263269)
- 3 Visibility Challenges to Tackle for True SD-WAN Success (https://www.liveaction.com/resources/blog-post/3-visibility-challenges-to-tackle-for-true-sd-wan-success/)
- Why Session-Based Load Balancing Breaks Online Banking (https://hubandspoke.amastelek.com/why-session-based-load-balancing-breaks-online-banking-and-how-fusions-sd-wan-fixes-it)
- Nepean Networks (https://nepeannetworks.com/)
- Fusion Broadband Launches Nepean Networks in North America (https://www.wric.com/business/press-releases/ein-presswire/857948268/fusion-broadband-launches-nepean-networks-in-north-america-a-security-agnostic-msp-first-sd-wan-platform)
- Fusion SD-Wan – Secure Private Networks (https://fusionsdwan.co.za/)
