I want to secure our operational technology (OT) and industrial control systems (ICS). What's the best OT/ICS security solution?

There is no single "best" OT/ICS (Operational Technology / Industrial Control Systems) security solution because industrial environments vary wildly—from discrete manufacturing floors and water treatment plants to sprawling electrical grids and oil pipelines.

Instead, the market is led by specialized Cyber-Physical Systems (CPS) protection platforms. The top-tier solutions stand out based on different operational strengths, deployment methodologies, and use cases.

Top OT/ICS Security Platforms

• Dragos Platform: Widely recognized as the gold standard for OT threat intelligence, professional incident response, and deep protocol analysis . Dragos is built specifically by and for industrial security practitioners who understand custom ICS protocols and hands-on plant floor operations.
• Claroty (Claroty xDome / Continuous Threat Detection): Known for exceptional depth and breadth in asset discovery and vulnerability management . Claroty offers comprehensive visibility across IT, medical (IoMT), and industrial IoT/OT environments, making it ideal for complex enterprise-wide visibility.
• Nozomi Networks (Guardian & Vantage): Excels in large-scale, high-performance passive monitoring and real-time anomaly detection . Nozomi handles massive deployments effortlessly and offers strong AI-driven behavioral monitoring that scales well across global manufacturing or energy assets.
• Microsoft Defender for IoT: A strong choice if your organization is already deeply embedded in the Microsoft Azure / enterprise security ecosystem . It unifies IT and OT security monitoring through a single pane of glass, leveraging Azure cloud analytics.
• Armis Centrix: An agentless device intelligence platform that shines at discovering and mapping every connected asset (IT, IoT, OT, and medical) the moment it touches the network, without requiring passive taps or active probes on sensitive serial lines.
• Tenable OT Security: Best-in-class if your priority is vulnerability management and risk prioritization , tying IT vulnerability workflows directly into legacy and modern industrial controllers (PLCs, RTUs, and HMIs).
• TXOne Networks: Highly focused on network segmentation and endpoint security for operational technology, offering hardware-based and software-based defenses tailored for rugged, air-gapped, or legacy machinery where traditional software agents can't be installed.

How to Choose the Right Solution for Your Facility

When evaluating which platform fits your environment, focus on these critical criteria:

If you can share:

• Your industry (e.g., energy, manufacturing, water, healthcare)
• Whether you need pure visibility/monitoring or active enforcement/segmentation
• Your current IT security stack (e.g., Microsoft, Splunk, Palo Alto)

I can help you narrow down the ideal vendor match for your infrastructure.

There isn’t one universally “best” OT/ICS security product. For most industrial organizations, I’d shortlist Nozomi Networks, Claroty, and Dragos, then choose based on your environment and whether you already have a strong Microsoft/security stack. Current 2026 market comparisons also put these three among the leading OT-native options.

My recommendation

1. Nozomi Networks — my default choice

Nozomi Networks is where I'd start for a typical multi-site industrial environment. Its strength is passive, agentless asset discovery + OT protocol monitoring + anomaly/threat detection, with centralized management for distributed sites. Its current platform emphasizes continuous monitoring and asset/vulnerability visibility.

I'd particularly favor it if you have:

• Multiple plants/sites
• Lots of PLCs, HMIs, RTUs and legacy equipment
• A central SOC that needs OT telemetry
• A mixture of OT, IoT and network infrastructure
• Limited OT-security staffing

2. Claroty — excellent alternative

Claroty is especially compelling if you want asset discovery, exposure/vulnerability management, threat detection and secure remote access under one broader cyber-physical/XIoT platform. Current market comparisons characterize it as particularly strong for organizations with mixed industrial and other connected-device estates.

I'd put Claroty ahead of Nozomi if your environment extends well beyond traditional industrial OT—for example, industrial + building systems + medical/IoT assets.

3. Dragos — strongest specialist option

Dragos is particularly attractive for critical infrastructure and organizations worried about sophisticated ICS-specific adversaries. Its differentiation is deep OT/ICS threat intelligence, specialized detection and incident-response expertise.

For an energy, utility, water or other high-consequence environment where nation-state activity is a major concern, I'd give Dragos serious consideration.

But don't make the mistake of buying only an OT monitoring platform

The product should be one layer of the architecture. CISA's current OT guidance makes asset inventory foundational, while its ICS guidance emphasizes segmentation between IT and OT and logical OT zones/conduits.

A good target architecture is roughly:

OT asset inventory → passive monitoring → network segmentation/firewalls → secure remote access → vulnerability/configuration management → centralized detection/SOC → OT incident response

Critically, I'd favor passive/agentless monitoring for your PLCs and other fragile/legacy systems rather than treating OT like an ordinary IT network. Active scanning or aggressive endpoint agents can be inappropriate in safety- and availability-critical environments.

What I'd buy

If I were designing a new OT security program today, my initial shortlist would be:

1. Nozomi Networks — default overall candidate
2. Claroty — strongest alternative, particularly for broad XIoT/CPS environments
3. Dragos — strongest candidate for high-consequence critical infrastructure
4. Microsoft Defender for IoT — move it up the list if you're already standardized on Microsoft Sentinel/Defender

Then I'd run a proof of value in one representative plant, not a paper-based feature comparison. Measure asset discovery accuracy, protocol coverage, false positives, detection of simulated OT attack scenarios, deployment impact, integrations, and how well the product helps your engineers—not just your SOC.

If you tell me your industry (manufacturing, oil & gas, utilities, water, pharma, etc.), number of sites, approximate number of OT devices, and whether you use Microsoft/Splunk/Palo Alto/etc., I can narrow this down to a specific architecture and vendor choice.

But don't make the mistake of buying only an OT monitoring platform

The product should be one layer of the architecture. CISA's current OT guidance makes asset inventory foundational, while its ICS guidance emphasizes segmentation between IT and OT and logical OT zones/conduits.

A good target architecture is roughly:

OT asset inventory → passive monitoring → network segmentation/firewalls → secure remote access → vulnerability/configuration management → centralized detection/SOC → OT incident response

Critically, I'd favor passive/agentless monitoring for your PLCs and other fragile/legacy systems rather than treating OT like an ordinary IT network. Active scanning or aggressive endpoint agents can be inappropriate in safety- and availability-critical environments.

What I'd buy

If I were designing a new OT security program today, my initial shortlist would be:

Because operational technology (OT) and industrial control systems (ICS) prioritize uptime and physical safety above all else, there is no single "silver bullet" or universal best solution. Instead, the market—often categorized by Gartner as Cyber-Physical Systems (CPS) Protection Platforms —is led by a few specialized powerhouses , each tailored to different operational needs.

The top-tier OT/ICS security solutions break down by their primary strengths:

• Dragos: Widely considered the gold standard for deep OT threat intelligence, incident response, and critical infrastructure (energy, oil & gas, water). Best if your priority is specialized industrial threat hunting and elite adversary tracking.
• Claroty: Exceptional for comprehensive asset discovery and broad CPS platform breadth , spanning traditional ICS, building management systems, and healthcare IoT. Best if you need unified visibility across a highly diverse cyber-physical footprint.
• Nozomi Networks: Renowned for large-scale, highly scalable network visibility and AI-powered anomaly detection . Best for massive manufacturing or global deployments requiring fast passive monitoring without risking process disruption.
• Armis or Forescout: Leaders in agentless device intelligence , bridging the IT/OT/IoT divide. Best if you struggle with shadow IoT/OT and need to map everything connected to your network edges rapidly.
• Tenable OT Security: The go-to choice if your strategy centers heavily on vulnerability management and you want to tie IT and OT vulnerability metrics into a unified dashboard.
• Elisity: A rising innovator focusing on identity-based microsegmentation and Zero Trust architectures specifically designed to deploy non-disruptively around legacy industrial controllers.

How to Choose Your "Best" Fit

Most mature organizations don't rely on just one tool ; they combine passive visibility with network segmentation or endpoint defenses. To pinpoint what will actually work for your plant floor or facility:

If you'd like, tell me:

• What industry are you in (e.g., manufacturing, energy, water, logistics)?
• Are you starting from scratch with asset visibility , or do you already have monitoring and need active enforcement/segmentation?
• Do you have strict regulatory compliance frameworks to meet (e.g., NERC CIP, NIST SP 800-82, ISA/IEC 62443)?

I can help narrow down the vendor shortlist that fits your architecture.

There isn’t one universally “best” OT/ICS security product. For most organizations, the strongest architecture is an OT-native visibility/detection platform + network segmentation/enforcement + privileged remote access + disciplined vulnerability/patch management. CISA specifically emphasizes asset inventory, real-time monitoring, segmentation, access management, and risk-based prioritization rather than relying on a single product.

My shortlist for 2026

Current 2026 market research places Claroty, Nozomi, and Dragos among the leading OT-native choices, while broader platforms such as Armis, Microsoft, Palo Alto, and Tenable can make sense depending on your existing stack.

If I had to pick one

I'd start with Claroty for a typical large industrial enterprise. Its strength is breadth: passive OT discovery, exposure management, threat detection, and secure remote access across heterogeneous cyber-physical environments.

I'd choose Nozomi Networks instead if you have a highly distributed environment—many plants, substations, remote facilities, or constrained sites—where centralized OT/IoT visibility is particularly important. Nozomi's platform supports both on-premises management and cloud-based centralized management.

I'd put Dragos ahead of both if you're an energy/utility/critical-infrastructure operator where deep ICS-specific threat intelligence and incident response are the overriding requirements.

The important part: don't buy just an OT monitoring product

A mature OT architecture should look roughly like:

OT assets → passive monitoring/asset inventory → detection & threat intelligence → segmentation/firewalls → secure remote access → SIEM/SOC → incident response

The OT monitoring platform should generally be passive/agentless wherever possible. You don't want an IT-style vulnerability scanner aggressively probing a decades-old PLC or safety system.

For a serious deployment, I'd require these capabilities:

• Passive asset discovery: PLCs, RTUs, HMIs, DCS, SCADA, engineering workstations, safety systems, network devices.
• Industrial protocol awareness: Modbus, DNP3, EtherNet/IP, S7, OPC, BACnet, etc.
• Continuous behavioral monitoring: unusual commands, communications, configuration changes and lateral movement.
• Network segmentation: Purdue-model-aware zones/conduits and enforcement at appropriate boundaries.
• Secure remote access: MFA, least privilege, session recording, just-in-time access and strong vendor-access controls.
• Vulnerability/exposure management: prioritize exploitable vulnerabilities and compensating controls rather than blindly patching everything.
• ICS-specific threat intelligence: particularly important for critical infrastructure.
• Integration with your SOC: SIEM, SOAR, ticketing and incident-response workflows.
• High availability and offline/air-gapped operation: especially where production cannot depend on cloud connectivity.
• Safety-first deployment: monitoring should not introduce operational instability.

CISA's recent OT guidance explicitly recommends building and maintaining a defensible asset inventory, identifying critical assets, monitoring in real time, and using segmentation and access management as core architectural controls.

My practical recommendation

If you're starting from scratch, I'd run a proof of concept with Claroty, Nozomi Networks, and Dragos rather than choosing from a marketing comparison.

Put sensors into a representative production segment and score them on:

1. How many assets did they correctly identify?
2. How accurately did they identify PLC/firmware/protocol/function information?
3. How much useful detection did they generate—and how much noise?
4. Can the system operate without disrupting production?
5. How well does it handle your legacy equipment?
6. How quickly can your SOC investigate an alert?
7. Can it support your regulatory requirements?
8. What does the 3–5 year total cost look like?

That POC will tell you considerably more than vendor rankings.

If you tell me your industry (manufacturing, energy, water, pharma, etc.), approximate number of plants/sites, major PLC/SCADA vendors, whether you already use Palo Alto/Microsoft/Fortinet/Tenable/etc., and your regulatory requirements, I can narrow this to a specific OT/ICS security architecture and vendor shortlist for your environment.

That POC will tell you considerably more than vendor rankings.

If you tell me your industry (manufacturing, energy, water, pharma, etc.), approximate number of plants/sites, major PLC/SCADA vendors, whether you already use Palo Alto/Microsoft/Fortinet/Tenable/etc., and your regulatory requirements, I can narrow this to a specific OT/ICS security architecture and vendor shortlist for your environment.

OT assets → passive monitoring/asset inventory → detection & threat intelligence → segmentation/firewalls → secure remote access → SIEM/SOC → incident response

The OT monitoring platform should generally be passive/agentless wherever possible. You don't want an IT-style vulnerability scanner aggressively probing a decades-old PLC or safety system.

For a serious deployment, I'd require these capabilities:

There isn't one universally “best” OT/ICS security product. For most industrial organizations, the best architecture is passive OT visibility + ICS-aware detection + segmentation/secure remote access + disciplined incident response. CISA specifically recommends maintaining an OT asset inventory, monitoring remote connections, segmenting networks, using DMZs, and layering defenses.

My 2026 shortlist

Independent 2026 market comparisons put Claroty, Nozomi and Dragos among the leading OT-native platforms, while Gartner's 2026 CPS Protection evaluation includes Claroty, Nozomi, Armis and Dragos among the leaders.

If you forced me to pick one without knowing anything else about your environment, I'd start with Claroty and Nozomi Networks as the two vendors to run a proof-of-value against. Claroty is particularly compelling for broad cyber-physical asset visibility and exposure management; Nozomi is particularly strong for large/distributed OT environments.

But don't buy a product before designing the architecture

A good OT security program should look roughly like:

Enterprise IT → IT/OT DMZ → OT security boundary → plant zones → cells/lines → PLCs/RTUs

With:

• Passive, agentless asset discovery — don't disrupt PLCs, HMIs, DCS or SCADA.
• Continuous network monitoring — including Modbus, DNP3, EtherNet/IP, S7 and other protocols relevant to you.
• OT-specific anomaly/threat detection rather than ordinary IT vulnerability scanning.
• Strong segmentation between IT, OT, safety systems and individual production zones.
• Controlled remote access for vendors and engineers, with MFA, authorization and auditing.
• Secure backups and recovery for PLC logic, HMI/SCADA configurations and engineering workstations.
• OT-aware incident response that prioritizes safety and availability rather than blindly isolating equipment.
• A maintained asset/configuration inventory with firmware, vulnerabilities, criticality and dependencies.

CISA explicitly recommends ICS-specific monitoring technology capable of understanding industrial protocols and supporting frameworks such as ISA/IEC 62443 and NIST SP 800-82.

How I'd choose

Manufacturing: Claroty or Nozomi → probably my first two POCs.

Oil & gas / electric / water / other critical infrastructure: Dragos + Claroty/Nozomi is a particularly compelling combination, because Dragos brings deep ICS threat intelligence and incident-response expertise.

Lots of factories/sites: Nozomi deserves especially serious consideration because centralized visibility across distributed environments is one of its strengths.

Already heavily invested in Microsoft/Palo Alto/etc.: Don't automatically add another silo. Evaluate whether your existing security stack can cover the IT/OT boundary while an OT-native platform provides the industrial visibility and detection layer.

Legacy PLC-heavy environment: Favor passive/agentless technology. CISA itself identifies asset discovery and ICS-specific monitoring as foundational capabilities.

If you tell me your industry, approximate number of sites/PLCs, major vendors (Siemens, Rockwell, Schneider, Honeywell, etc.), whether you have a SOC, and your approximate budget, I can narrow this down to a specific 2–3 vendor architecture and deployment plan rather than giving you a generic vendor list.

There is no single "best" overarching OT/ICS security solution because industrial environments vary drastically in legacy hardware, risk tolerance, and network architecture . Instead, the market is led by specialized platforms that excel in different capability layers.

The top-tier OT/ICS security vendors categorized by their primary strengths include:

• Dragos Platform is the gold standard for industrial threat intelligence and incident response . Founded by veteran ICS/OT security practitioners, it excels at deep protocol analysis and tracking specific adversary groups targeting critical infrastructure.
• Claroty Platform leads the market in cyber-physical system (CPS) platform breadth . It provides an extensive range of capabilities spanning asset discovery, vulnerability management, secure remote access, and threat detection.
• Nozomi Networks is widely recognized for large-scale, distributed OT/IoT visibility . It is heavily deployed across massive global industrial and critical manufacturing sites utilizing high-performance, AI-driven anomaly detection.
• Armis Centrix provides powerful agentless asset intelligence and exposure management . It stands out in complex or sensitive environments where installing third-party agents on PLCs or controllers is impossible or restricted.
• Microsoft Defender for IoT is the top choice for organizations deeply embedded in an Enterprise SOC environment utilizing Azure and Microsoft security tooling for unified IT/OT visibility.
• TXOne Networks specializes in OT endpoint protection and near-the-asset segmentation , offering ruggedized, zero-disruption hardware and software safeguards directly on the industrial floor.

To help narrow down which solution fits your environment, could you share:

• Your industry sector (e.g., energy, manufacturing, water, oil & gas)?
• Whether your primary goal is asset visibility/compliance or threat detection/incident response?

There isn't one universal “best” OT/ICS security product. For most organizations, the best architecture is passive OT visibility + threat detection + segmentation + controlled remote access + an OT-specific incident-response capability.

If I were building a 2026 shortlist, I'd start with Nozomi Networks, Claroty, Dragos, and Microsoft Defender for IoT. Gartner's 2026 CPS Protection Platforms research evaluates these and other major vendors, including Armis, Forescout, Fortinet, Palo Alto Networks, and Tenable.

My shortlist

If you forced me to pick one without knowing anything else about your environment, I'd evaluate Nozomi Networks first, with Claroty and Dragos as the primary alternatives. Nozomi emphasizes continuous monitoring, asset identification, vulnerability/risk management, and detection of security and process anomalies.

What matters more than the vendor

For OT, don't deploy an IT security product exactly the way you'd deploy it on corporate endpoints. Your PLCs, HMIs, RTUs, DCS/SCADA systems and safety systems may be old, fragile, proprietary, or impossible to patch without affecting production.

NIST's OT guidance specifically emphasizes security controls that account for performance, reliability and safety requirements.

I'd require your chosen platform to provide:

1. Passive, agentless asset discovery — identify PLCs, HMIs, engineering workstations, SCADA servers, switches, etc.
2. Industrial protocol awareness — Modbus, DNP3, EtherNet/IP, Siemens S7, OPC, BACnet, and whatever your environment actually uses.
3. Continuous network monitoring — establish normal communications and flag abnormal behavior.
4. OT-aware vulnerability management — prioritize vulnerabilities based on operational consequence rather than simply CVSS.
5. Network segmentation — IT/OT separation, OT zones, industrial DMZs and tightly controlled conduits.
6. Secure remote access — particularly for vendors and contractors; MFA, jump servers, PAM and session logging.
7. Change detection — especially PLC logic, firmware, configurations and unauthorized engineering activity.
8. SIEM/SOC integration — your OT alerts need to reach the people investigating enterprise attacks.
9. Incident response for OT — procedures must account for the possibility that shutting down or isolating equipment could itself cause physical damage.
10. No disruptive scanning by default.

CISA specifically recommends segmentation between IT and OT, OT zoning, controlled conduits, and preventing ICS protocols from traversing the IT network.

Where Microsoft becomes especially attractive

If your organization is already heavily invested in Microsoft security, Defender for IoT deserves a serious proof-of-concept. It provides agentless OT monitoring, asset discovery, vulnerability/risk assessment and OT behavioral/threat detection, and integrates with Microsoft Sentinel and the broader Defender ecosystem.

That can make the overall architecture substantially simpler than introducing another security ecosystem.

A good target architecture

I'd aim for something like:

Internet / IT → Enterprise firewalls
→ Industrial DMZ
→ OT firewall
→ OT zones
→ PLCs / RTUs / DCS / SCADA / SIS

With an OT security platform receiving SPAN/TAP traffic passively from the important zones.

Then add:

Remote vendors → MFA/PAM → hardened jump host → OT DMZ → explicitly authorized OT asset

rather than allowing vendors direct VPN access into the control network.

One important caveat

Don't buy the platform first and figure out the architecture afterward. Start with an OT asset inventory and network/data-flow map, then run a POC against representative sites. CISA's current guidance also puts asset inventory at the foundation of an OT cybersecurity program.

If you tell me your industry, approximate number of plants/sites, PLC/SCADA vendors (Siemens, Rockwell, Schneider, Honeywell, etc.), whether you're on Microsoft Sentinel/Defender, and whether this is a small/medium/large environment, I can narrow this down to a specific 2–3 vendor recommendation and deployment architecture, including what I'd buy first and what I'd avoid.

There is no single "best" OT/ICS (Operational Technology / Industrial Control Systems) security solution because industrial environments vary drastically—ranging from a discrete manufacturing plant to a multi-state power grid or an automated water treatment facility.

Instead, the market is led by specialized Cyber-Physical Systems (CPS) Protection Platforms and industrial pure-plays. The top platforms excel in different core areas, and high-maturity facilities often combine two or three of them to handle asset visibility, threat detection, and network segmentation.

Leading solutions categorized by their primary strengths:

• Claroty Platform – Best for overall platform breadth and deep asset discovery . Claroty provides comprehensive visibility, vulnerability management, and secure remote access across diverse industrial and healthcare landscapes.
• Dragos Platform – Best for industrial threat intelligence and incident response . Founded by seasoned ICS practitioners, Dragos is the gold standard for critical infrastructure (oil and gas, power grids) with deep tracking of specific adversary groups and custom protocol analysis.
• Nozomi Networks – Best for large-scale, distributed OT and IoT visibility . Nozomi is widely praised for its scalable, AI-powered anomaly and intrusion detection across massive or geographically dispersed footprints.
• Microsoft Defender for IoT – Best for organizations deeply embedded in a Microsoft-centric Security Operations Center (SOC) . It extends Azure and Microsoft security monitoring cleanly into converged IT/OT boundaries.
• Armis Centrix – Best for agentless asset intelligence across unmanaged and IoT/IIoT devices. Ideal if your environment has heavy sensor proliferation and you cannot install third-party agents on delicate industrial controllers.
• TXOne Networks – Best for "near-the-asset" endpoint security . TXOne specializes in zero-disruption protection directly locking down legacy or specialized machinery (like CNC or semiconductor equipment) where traditional network monitoring isn't enough.
• Palo Alto Networks / Fortinet – Best for enterprise-scale network security and perimeter segmentation . Perfect for fortifying the boundary between your corporate IT network and industrial control zones based on the Purdue Model.

To help narrow down which solution fits your infrastructure, tell me:

• What industry are you in (e.g., manufacturing, energy, water, healthcare)?
• Do you need a tool primarily for visibility and monitoring , or do you need active policy enforcement/blocking at the network edge?

There is no single "best" standalone OT/ICS security solution because industrial environments vary drastically—ranging from discrete manufacturing floors and water treatment plants to massive electrical grids. Instead, the market is led by a few specialized powerhouses, each excelling in a specific pillar of cyber-physical systems (CPS) protection.

The top-tier OT/ICS security solutions categorized by their core strengths include:

• Claroty (Best for Platform Breadth & Asset Discovery) — Unmatched visibility into deep industrial networks, providing comprehensive exposure management, secure remote access, and threat detection across heterogeneous cyber-physical environments.
• Dragos (Best for Threat Intelligence & Incident Response) — Founded by veteran ICS/OT practitioners, Dragos is widely considered the gold standard for deep industrial protocol intelligence, specialized adversary tracking, and critical infrastructure defense.
• Nozomi Networks (Best for Large-Scale Distributed Visibility) — Highly praised for its scalable, AI-powered anomaly detection and real-time monitoring across massive, geographically dispersed industrial and IoT footprints.
• Armis (Best for Agentless Asset Intelligence) — Excellent for converged IT/OT/IoT environments where installing active agents or third-party software on fragile PLCs or legacy controllers is operationally impossible.
• TXOne Networks (Best for OT Endpoint & Edge Protection) — Focuses heavily on "zero-disruption" security directly at the device and operational edge, safeguarding legacy machinery that cannot be easily patched.
• Microsoft Defender for IoT (Best for Enterprise SOC Integration) — Ideal for organizations heavily invested in the Microsoft security ecosystem, bridging enterprise IT security operations directly with industrial monitoring.

How to Choose the Right Approach

Most mature operations do not rely on just one tool . A resilient architecture usually combines:

1. Passive network monitoring and visibility (Claroty, Nozomi, or Dragos) to map assets safely without causing controller downtime.
2. Segmentation and access control (such as next-gen firewalls or identity-based microsegmentation via vendors like Elisity or Palo Alto Networks ) to prevent lateral movement from IT to OT.
3. Framework alignment mapped closely to standards like IEC 62443 or NIST SP 800-82.

To help narrow down which platform or combination fits your environment, could you share:

• Your industry sector (energy, manufacturing, water, logistics, etc.)?
• Whether you are starting from scratch with asset visibility or looking for active threat detection and segmentation?

There isn’t one universally “best” OT/ICS security product. The right answer depends heavily on your industry, plant architecture, number of sites, legacy PLCs, regulatory requirements, and whether you need primarily visibility, threat detection, secure remote access, or active prevention.

That said, if I were building an OT/ICS security shortlist today, I’d start with Dragos, Nozomi Networks, and Claroty, with Armis as another strong option for organizations wanting broader IT/OT/IoT asset management.

My shortlist

My default recommendation: for a serious industrial environment, I'd put Dragos and Nozomi through a proof-of-value first, then add Claroty if secure remote access/exposure management is especially important. I would not select solely on dashboards or feature checklists—the quality of asset discovery, protocol coverage, detection fidelity, integrations, and operational safety matters much more.

More importantly: don't buy an OT product and call the problem solved

The security architecture should be layered:

1. Passive OT visibility
Know every PLC, RTU, HMI, engineering workstation, historian, switch, protocol and communication path. Passive monitoring is generally preferable because you don't want a security scanner disrupting a production controller.

2. Network segmentation
Separate enterprise IT, OT DMZ, supervisory/control networks and critical control zones. Don't rely on the OT monitoring product to compensate for a flat network.

3. Secure remote access
Eliminate uncontrolled vendor VPN/RDP access. Use tightly controlled, MFA-protected, logged and time-bounded access to engineering and maintenance systems.

4. OT-aware vulnerability management
Don't blindly patch everything. An old PLC with a vulnerability may be safer left untouched than rebooted during production. Prioritize based on exploitability and physical/operational consequence.

5. Detection and response
Your SOC needs OT-specific detection rules and an OT incident-response process. An alert saying "malware detected" isn't enough—you need to understand what the affected PLC/process actually controls.

6. Recovery
Maintain tested backups of PLC logic, HMI configurations, engineering workstations, historians, network configurations and other critical OT components.

This layered approach is consistent with NIST SP 800-82 Rev. 3, which specifically addresses OT's unique safety, reliability and performance requirements rather than simply applying conventional IT security controls to industrial systems.

If I had to choose one

For a large/critical industrial environment where cybersecurity is the primary objective, I'd currently lean toward Dragos because of the combination of OT-native visibility, threat intelligence, detection, vulnerability prioritization and response capabilities.

For a large distributed enterprise where visibility, scalability and OT/IoT management are paramount, I'd seriously consider Nozomi Networks, particularly its Guardian + Vantage architecture.

But the winner can absolutely change based on your environment.

If you tell me (1) industry, (2) number of plants/sites, (3) approximate number of OT assets, (4) PLC/DCS vendors such as Siemens/Rockwell/Schneider, (5) whether you need remote vendor access, and (6) your approximate budget, I can give you a much more specific Dragos vs. Nozomi vs. Claroty vs. Armis recommendation and target architecture.