For decades, the Purdue Model served as the gold standard for industrial network segmentation. But in today’s hyper-connected landscape, the “Level 3.5” DMZ is often bypassed by vendors using unmanaged cellular hotspots or weak VPNs.
The challenge for CISO and OT Managers today is balancing operational uptime with security integrity. Unlike IT environments where a “reboot” is a minor inconvenience, in OT, an unauthorized remote command can lead to physical damage, environmental hazards, or loss of life.
Why Traditional VPNs are Failing OT
Standard IT VPNs provide a “tunnel” into the network. Once inside, an attacker often has broad lateral movement capabilities. In an industrial setting, this is catastrophic. Modern solutions have moved toward Secure Remote Access (SRA) and Zero Trust Network Access (ZTNA), which focus on:
- Granular Protocol Inspection: Understanding the difference between a “Read” and a “Write” command in Modbus or S7.
- Identity-Centric Access: Ensuring the user is who they say they are and that their device is compliant.
- Session Termination: Automatically killing sessions that show anomalous behavior.
Top 15 Remote Access Security Solutions for OT Networks
Here is our curated list of the industry-leading solutions specifically designed or adapted for the rigorous demands of Cyber-Physical Systems (CPS).
1. Claroty (xDome & SRA)
Claroty has emerged as a powerhouse in the 2025 Gartner® Magic Quadrant™ for CPS Protection. Their Secure Remote Access (SRA) is purpose-built for industrial environments, offering a “clientless” experience that doesn’t require installing software on sensitive HMI stations.
- Key Feature: Full session recording and auditing for compliance with NIS2 and NERC-CIP.
- Best For: Large-scale enterprises requiring deep protocol visibility.
2. BeyondTrust Privileged Remote Access
BeyondTrust is a leader in managing “who gets in.” Their solution excels at injecting credentials so that third-party vendors never actually see the passwords to your PLCs.
- Key Feature: Just-in-Time (JIT) access, which grants permissions only for the duration of the maintenance window.
- Best For: Organizations with heavy third-party vendor management needs.
3. Dragos Platform
While known for threat intelligence, the Dragos platform provides an integrated look at remote access logs to detect “living-off-the-land” attacks-where hackers use legitimate tools to do harm.
- Key Feature: Expert-driven “Knowledge Packs” that translate raw traffic into actionable OT insights.
- Best For: High-consequence environments like power grids and water utilities.
4. Nozomi Networks (Guardian & Vantage)
Nozomi specializes in the “visibility” aspect of remote access. Their Vantage platform allows for cloud-based monitoring of all remote connections across global sites.
- Key Feature: AI-powered behavioral baselining that alerts you if a remote user starts “scanning” the network.
- Best For: Global manufacturing firms with distributed plants.
5. Fortinet (FortiGate & FortiTrust)
Fortinet has integrated OT-specific features directly into their Security Fabric. By using ruggedized FortiGate firewalls, they provide a secure entry point that can withstand harsh factory floor conditions.
- Key Feature: Integrated ZTNA (Zero Trust Network Access) that verifies users every time they request access to a specific asset.
- Best For: Environments looking for a unified IT/OT hardware stack.
6. Cisco Cyber Vision
Cisco leverages its dominant position in industrial switching to provide “edge-based” security. Cyber Vision identifies exactly what remote users are doing by analyzing traffic directly at the switch port.
- Key Feature: Deep integration with Cisco ISE for automated policy enforcement.
- Best For: Users already heavily invested in Cisco industrial networking hardware.
7. Palo Alto Networks (Prisma Access for OT)
Prisma Access provides a cloud-delivered security service that extends the corporate “perimeter” to the most remote wellhead or substation.
- Key Feature: ML-powered threat prevention that stops zero-day OT exploits in real-time.
- Best For: Companies moving toward a SASE (Secure Access Service Edge) architecture.
8. Xage Security
Xage uses a unique “Fabric” approach based on identity-based access control. It’s one of the few solutions that can bring Zero Trust to “un-patchable” legacy systems.
- Key Feature: Decentralized security that ensures there is no “single point of failure” for an attacker to target.
- Best For: Critical infrastructure with highly sensitive, legacy components.
9. Cyolo
Cyolo is a “Zero Trust Access” specialist that doesn’t require a cloud connection—making it ideal for truly isolated OT environments that still need local remote management.
- Key Feature: High-speed deployment with no agents required on the endpoints.
- Best For: Sensitive sites that prioritize data sovereignty and local control.
10. Rockwell Automation (FactoryTalk Security)
As an OEM giant, Rockwell understands the “process” better than anyone. Their security suite is designed to integrate seamlessly with their own automation hardware.
- Key Feature: Granular control over FactoryTalk applications and user roles.
- Best For: Facilities running predominantly Rockwell/Allen-Bradley ecosystems.
11. Honeywell Forge Cybersecurity
Honeywell Forge provides a “Secure Media Exchange” and remote access portal that focuses heavily on the safety of the industrial process.
- Key Feature: Simplified “one-click” audit reporting for regulatory compliance.
- Best For: Oil & Gas and Chemical processing plants.
12. Waterfall Security Solutions (Unidirectional Gateways)
Strictly speaking, Waterfall is “Remote Access” in reverse. They use hardware-enforced “One-Way” data diodes to allow data to flow out for monitoring without allowing any signals to flow in.
- Key Feature: Absolute physical protection against remote attacks.
- Best For: Nuclear plants and ultra-high-security critical infrastructure.
13. Check Point (Quantum Rugged)
Check Point offers specialized industrial firewalls with “Virtual Patching” capabilities, protecting remote access points from known vulnerabilities even if the underlying PLC isn’t updated.
- Key Feature: ThreatCloud AI, which provides global threat intelligence sharing.
- Best For: Heavy industrial sectors like mining and shipping.
14. Tenable.ot (now part of Tenable One)
Tenable provides deep asset inventory and vulnerability management. Their remote access security focuses on identifying the risk of a connection before it is even made.
- Key Feature: “Snapshots” of PLC logic to detect changes made during a remote session.
- Best For: Compliance-heavy industries needing detailed “before and after” change logs.
15. OPSWAT (MetaAccess OT)
OPSWAT focuses on “Peripheral Security.” They ensure that any device attempting to connect remotely isn’t bringing in malware via files or “dirty” endpoint status.
- Key Feature: Deep CDR (Content Disarm and Reconstruction) for files transferred during remote sessions.
- Best For: Environments where file transfers are a frequent part of maintenance.
Strategic Implementation: How to Choose?
When selecting a solution for your OT Ecosystem, consider the following “Golden Rules” of industrial remote access:
1. The “Safety-First” Filter
In IT, “CIA” (Confidentiality, Integrity, Availability) is the priority. In OT, it is “AIC” with an extra “S” for Safety. Any remote access tool must prove that it will not accidentally crash a PLC by sending high-frequency polling packets or non-standard protocol requests.
2. Protocol Depth vs. Generic Access
Don’t settle for a tool that just sees “Traffic.” You need a tool that sees “Function Codes.” If a remote user tries to change the “Set Point” on a boiler, your security system should know that specific action is happening and require a second-tier approval.
3. Compliance Mapping
With the rollout of NIST SP 800-82 Rev 3, regulators are looking for specific controls:
- Multi-Factor Authentication (MFA): Is it mandatory for all remote users?
- Least Privilege: Does the vendor have access to the whole network or just one IP address?
- Auditability: Can you play back the session to see exactly what the technician clicked?
Conclusion: Securing the Future of Industry
The “OT Ecosystem” is no longer a static collection of machines; it is a dynamic, living network. Securing remote access is the first and most critical line of defense in protecting the physical world from digital threats. By moving away from legacy VPNs and adopting one of the 15 leaders mentioned above, industrial operators can embrace the benefits of digital transformation without sacrificing the safety of their operations.