Background: Why Industrial VPNs Matter More Than Ever in OT/ICS
Remote maintenance has become a non-negotiable requirement across industrial environments-manufacturing plants, oil & gas facilities, power utilities, water treatment plants, and smart infrastructure. OEMs, system integrators, and internal OT teams now routinely access PLCs, SCADA systems, HMIs, and industrial IoT devices from remote locations.
However, this connectivity comes with significant cybersecurity risks.
Unlike traditional IT VPNs, industrial VPN solutions must operate reliably in harsh environments, support legacy protocols, and align with OT security standards such as IEC 62443, NIST SP 800-82, and modern Zero Trust principles. They must also account for:
- Long equipment lifecycles (15-30 years)
- Legacy operating systems and protocols
- Safety-critical and availability-focused systems
- Limited tolerance for latency or downtime
Over the past few years, high-profile ransomware attacks on industrial infrastructure have demonstrated that flat networks, shared credentials, and generic IT VPNs are no longer acceptable for remote access into OT environments.
Industrial VPN solutions have evolved to address these realities by offering:
- Asset-level access control
- Encrypted tunnels designed for OT protocols
- Identity-aware and policy-based access
- Integration with industrial firewalls and secure remote access gateways
This article provides an up-to-date, non-generic, OT-focused analysis of the Top 20 Industrial VPN Solutions for Remote Maintenance in 2025, helping asset owners and security leaders make informed decisions.
What Defines an Industrial-Grade VPN Solution?
Before exploring vendors, it’s important to clarify what separates industrial VPNs from traditional IT VPNs.
Key Characteristics of Industrial VPNs
- Designed for OT/ICS availability and determinism
- Supports industrial protocols (Modbus, PROFINET, EtherNet/IP, DNP3)
- Works in segmented and zone-based architectures
- Aligns with IEC 62443-3-3 and 62443-4-2
- Enables vendor and contractor access without exposing full networks
- Supports unidirectional or tightly controlled bidirectional communication
Top 20 Industrial VPN Solutions for Remote Maintenance
1. Siemens – SCALANCE S Industrial VPN
Siemens’ SCALANCE S portfolio is purpose-built for industrial environments. It enables secure VPN tunnels between machines, plants, and remote engineers while integrating tightly with Siemens TIA Portal and industrial firewalls.
Best for: Siemens-centric OT environments and large industrial plants
Strength: Deep IEC 62443 alignment and long-term lifecycle support
2. Phoenix Contact – mGuard Secure VPN
Phoenix Contact’s mGuard devices are widely used for secure remote maintenance of machines and substations. They provide hardened VPN connectivity and role-based access tailored for OT teams and OEMs.
Best for: Machine builders and critical infrastructure
Strength: Ruggedized hardware and strong segmentation
3. Hirschmann – Industrial VPN Routers
Hirschmann industrial routers support encrypted VPN tunnels optimized for industrial Ethernet environments, making them ideal for harsh and distributed OT networks.
Best for: High-availability industrial networking
Strength: Reliability and industrial network resilience
4. Fortinet – FortiGate Industrial VPN
Fortinet’s ruggedized FortiGate firewalls extend enterprise-grade VPN capabilities into OT environments with protocol awareness and segmentation.
Best for: Converged IT/OT security strategies
Strength: Unified firewall, VPN, and threat detection
5. Cisco – Cisco Industrial Secure VPN
Cisco’s industrial routers and secure VPN technologies provide encrypted remote access with integration into broader IT security ecosystems.
Best for: Large enterprises with Cisco IT infrastructure
Strength: Enterprise-scale identity and access management
6. Palo Alto Networks – Industrial Zero Trust VPN
Palo Alto extends its Zero Trust Network Access (ZTNA) principles into industrial networks through VPN-enabled segmentation and policy enforcement.
Best for: Zero Trust-driven OT security programs
Strength: Application-aware access control
7. Moxa – Secure Industrial VPN Gateways
Moxa specializes in industrial networking equipment designed for extreme conditions, offering VPN gateways optimized for remote site connectivity.
Best for: Utilities, transportation, and oil & gas
Strength: Environmental resilience and protocol support
8. Ewon – Ewon Cosy+
Ewon Cosy+ is a widely adopted remote access VPN solution for OEMs, enabling secure machine-level access without exposing plant networks.
Best for: OEM remote maintenance
Strength: Ease of deployment and vendor access control
9. Tosibox – Tosibox Industrial VPN
Tosibox offers plug-and-play industrial VPN solutions that eliminate complex configurations while maintaining strong encryption.
Best for: Fast deployment in distributed sites
Strength: Simplicity without sacrificing security
10. Secomea – GateManager
Secomea’s GateManager enables granular, role-based VPN access to OT assets with strong auditing and logging.
Best for: Vendor-managed industrial assets
Strength: Excellent access governance
11. SoftEther – SoftEther Industrial VPN
SoftEther provides flexible VPN software that can be adapted for industrial use cases with proper hardening and segmentation.
Best for: Custom industrial VPN deployments
Strength: Protocol flexibility
12. Red Lion Controls – Secure VPN Routers
Red Lion integrates VPN capabilities into industrial routers designed for SCADA and telemetry environments.
Best for: Industrial automation and remote telemetry
Strength: Seamless SCADA integration
13. Westermo – Industrial Secure VPN
Westermo focuses on mission-critical industrial networks, offering VPN solutions that prioritize availability and resilience.
Best for: Rail, power, and defense
Strength: Extreme reliability
14. GarrettCom – Magnum Secure VPN
GarrettCom devices support secure VPN tunneling within ruggedized industrial Ethernet networks.
Best for: Legacy industrial environments
Strength: Backward compatibility
15. INSYS icom – Industrial VPN Routers
INSYS icom delivers VPN-enabled routers tailored for industrial automation and smart infrastructure.
Best for: Smart grid and industrial IoT
Strength: Strong remote diagnostics
16. Opengear – Secure VPN Access
Opengear focuses on resilient remote access and out-of-band management with encrypted VPN connectivity.
Best for: Critical OT network recovery
Strength: Operational continuity
17. Barracuda Networks – Industrial VPN Gateways
Barracuda provides secure VPN gateways that can be deployed in industrial DMZ architectures.
Best for: Hybrid IT/OT security models
Strength: Strong threat protection
18. WatchGuard – Firebox Industrial VPN
WatchGuard’s Firebox devices bring VPN and firewall capabilities into rugged industrial deployments.
Best for: Mid-size industrial enterprises
Strength: Cost-effective security
19. Ubiquiti – Industrial VPN Solutions
Ubiquiti provides VPN-capable industrial networking hardware suitable for less critical OT use cases.
Best for: Non-critical industrial sites
Strength: Affordable scalability
20. Juniper Networks – Secure Industrial VPN
Juniper extends its secure networking portfolio into industrial deployments with policy-driven VPN access.
Best for: Large-scale industrial enterprises
Strength: High-performance encrypted networking
Key Trends Shaping Industrial VPNs in 2025
1. Shift from VPN-Only to Zero Trust Access
Industrial VPNs are increasingly integrated with identity-based access control, replacing always-on tunnels with session-based connectivity.
2. Vendor & Contractor Risk Management
Modern solutions limit what vendors can access, when, and for how long, significantly reducing third-party risk.
3. Integration with OT SOCs
VPN logs and session data are now fed into OT-aware SIEM and SOC platforms for real-time monitoring.
Final Thoughts
Industrial VPNs are no longer optional tools-they are foundational components of OT cybersecurity architectures. Selecting the right solution requires balancing security, availability, compliance, and operational simplicity.
Organizations that continue relying on generic IT VPNs for OT remote access expose themselves to unnecessary operational and safety risks. By adopting purpose-built industrial VPN solutions aligned with modern standards, asset owners can enable secure remote maintenance without compromising resilience.