Securing SCADA and ICS Networks with flexiWAN
Building Resilient, Secure, and Modern Connectivity for Critical Infrastructure
Published June 8, 2025.
In this article
The Changing Landscape of Industrial Networking
Security and Visibility with flexiWAN
Built on Linux, Open by Design
A Practical Example: Secure Access in a Water Utility Network
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Modern SCADA and ICS environments are evolving rapidly—integrating cloud services, supporting remote teams, and becoming more interconnected than ever. With that growth comes the need for smarter, more secure networking.
While progress has been made, many industrial systems remain exposed or inadequately segmented. The need to enhance security, improve visibility, and simplify access control continues in 2025.
flexiWAN, a modular SD-WAN platform, gives industrial operators the ability to meet these demands using open-source, policy-driven connectivity—without vendor lock-in.
The Changing Landscape of Industrial Networking
In recent years, a shift has taken place in how industrial systems are accessed and managed. From remote PLC programming to vendor diagnostics, connectivity is no longer optional—it’s part of daily operations.
However, public research and platforms Shodan or Censys searches reveal PLCs from vendors like Siemens, Schneider, or Allen-Bradley directly accessible online, with weak or no authentication. These include:
Web interfaces to PLCs and RTUs
OPC UA servers accessible over public IPs
HMI dashboards with default credentials
These findings highlight the need for modern, security-conscious access infrastructure that supports existing operations rather than disrupting them.
Security and Visibility with flexiWAN
flexiWAN is an open source SD-WAN & SASE solution built for the modern edge. It brings a secure, policy-based overlay to SCADA and ICS environments, making it easier to control, monitor, and protect infrastructure across multiple sites.
Key Features for Industrial Deployments
Secure Connectivity
Easy to deploy and automated IPsec tunnels between control centers and field locations
Traffic encryption and integrity by default
Granular Access Policies
Role-based controls for internal teams and external vendors
Define who can access what, and when
Segmentation and Isolation
Separate traffic between PLCs, sensors, HMIs, and corporate IT
Prevent lateral movement and reduce risk scope
Centralized Management and Monitoring
Visibility into all connections and sessions
Integration with SIEMs, logging tools, or third-party observability stacks
Edge Resilience
LTE/5G support for backup or remote sites
Flexible deployment on ruggedized hardware
Built on Linux, Open by Design
flexiWAN is not just modular—it’s also transparent. Running on open-source Linux, it gives operators complete control over the stack, from networking and routing to access enforcement and logging.
This means you can:
Inspect and harden the software you run
Choose exactly how your edge devices behave
Update securely and consistently across all locations Avoid the limitations of closed, vendor-managed appliances
This level of transparency and flexibility is especially valuable in security-conscious environments like ICS and SCADA.
A Practical Example: Secure Access in a Water Utility Network
A regional utility company needed to modernize how engineers and integrators accessed remote pump stations. The prior setup used manual VPN configurations and firewall rules across dozens of unmanaged routers.
With flexiWAN:
Each site was connected using a secure, policy-driven tunnel
Vendors received restricted access to only the equipment they were authorized to maintain
Session activity was logged centrally, and all exposure to public IPs was eliminated
No changes were required to the PLCs, HMIs, or SCADA software. The overlay provided by flexiWAN added security and visibility without interrupting operations.
Deployment Without Lock-In
With flexiWAN, you’re free to choose the hardware and deployment model that fits your environment:
Industrial PCs, fanless DIN-rail units, LTE-enabled edge routers
Virtual instances for control rooms or centralized environments
Tested platforms from our hardware vendors
You stay in control of the infrastructure—and the roadmap.
Ready to Secure Your SCADA or ICS Network?
If you’re looking to modernize and protect your industrial systems—whether it’s SCADA environments, PLCs, or remote sites—flexiWAN offers a flexible and secure way to do it, without locking you into a single vendor.
We work with organizations of all sizes to design reliable, policy-based connectivity that fits real-world industrial needs.
Have questions or want to explore how this could work for your setup? Get in touch with us to schedule a consultation and learn how flexiWAN can help.
