š¦Why Session-Based Load Balancing Breaks Online Banking ā & How Fusionās SD-WAN Fixes Itš
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Multi-WAN setups are essential for businesses looking for better uptime and resilience, but not all load balancing solutions are created equal. Many firewall-based SD-WAN solutions use session-based load balancing, which can cause serious problems for online banking, secure websites, and other session-sensitive applications.
If youāve ever had a banking session randomly disconnect or received a āsession expiredā error while making a payment, your firewallās load balancing may be the culprit.
The Problem with Session-Based Load Balancing
Most firewall-based SD-WAN solutions use session-based (or per-flow) load balancing to distribute traffic across multiple links. This means:
š¹ Each new session is randomly assigned to one of the available WAN links.
š¹ Subsequent traffic for that session stays on the same link until the session ends.
š¹ If one link fails, active sessions are dropped because they cannot move between links dynamically.
For many web applications, this method is "good enough", but it completely breaks online banking and secure logins.
Why Online Banking Fails with Session-Based Load Balancing
1ļøā£ Banking Security Detects IP Changes as a Threat
Most online banking platforms and secure websites use strict session security to prevent fraud. They track your IP address at login and expect all future requests to come from the same IP.
š“ With session-based load balancing, some banking requests (like authentication) may be sent over one ISP, while later requests (like payments) go over another.
š“ This triggers fraud detection and forces the session to be terminatedāresulting in session expiry or re-authentication loops.
2ļøā£ OTP Pages and Payment Gateways Fail Mid-Transaction
š“ 3D Secure (Verified by Visa / Mastercard SecureCode) relies on tracking your session IP. When session-based load balancing shifts the next request to another ISP, the banking server no longer recognises the session and throws an error.
š“ This can cause payments to fail or get stuck in an incomplete state.
3ļøā£ Firewall Load Balancers Donāt Handle Failover Seamlessly
If one ISP fails during an active banking session, a session-based load balancer cannot move the session to another WAN link. The result?
š“ The session is lost, and youāre logged out.
š“ You need to start over, re-login, and authenticate again.
For banking, session consistency is critical, and firewall-based SD-WAN solutions fail to deliver.
The Solution | Packet-Based Load Balancing with Fusionās SD-WAN
Fusionās packet-based SD-WAN load balancing avoids all these issues by ensuring:
ā
Every packet is dynamically assigned the best available WAN pathānot just the initial session.
ā
Session stickiness is maintained when required for banking and secure logins.
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Failover happens in real-time at the packet level, ensuring seamless recovery if a link goes down.
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The banking website sees only one IP address, preventing session expiry issues.
Unlike firewall-based load balancers, Fusionās SD-WAN bonds multiple internet links into a single, stable connectionāgiving your banking applications the reliability they need.
Why Fusionās SD-WAN is the Rock-Solid Choice
Fusionās SD-WAN doesnāt just offer better failover and resilienceāit completely eliminates the session-breaking pitfalls of firewall-based SD-WAN solutions.
š¹ True Multi-WAN Aggregation ā Uses all WAN links at the same time without breaking sessions.
š¹ Real-Time Packet Steering ā Ensures banking traffic always flows over a single IP.
š¹ Seamless Failover ā If an ISP fails, the transition is invisible to usersāno lost sessions.
š¹ Smart Routing ā Prioritises mission-critical traffic, like banking, VoIP, and video conferencing.
With Fusionās SD-WAN, online banking just worksāno frustrating disconnections, no failed transactions, and no wasted time.
Wrap
Firewall-based SD-WAN solutions break secure banking because they rely on outdated session-based load balancing. This method causes session expiry, login failures, and broken transactions due to IP switching across WAN links.
Fusionās packet-based SD-WAN is the rock-solid solution that keeps online banking stable and seamless. Instead of frustrating errors, users get:
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Consistent connectivity
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Secure, uninterrupted banking sessions
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Smooth, failover-proof transactions
If your business depends on reliable online banking, payments, and other session-sensitive applications, itās time to ditch firewall-based SD-WAN and switch to Fusionās next-generation SD-WAN. š
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Ronald Bartels
Ronald Bartels
Driving SD-WAN Adoption in South Africa