This is the third and final article in our three-part series on Network Intrusion Detection Systems (NIDS). If you missed the earlier parts, you can read Part 1 here and Part 2 here.
Network Intrusion Detection Systems (NIDS) play a central role in securing operational technology (OT) and industrial IoT (IIoT) environments. They facilitate passive monitoring of data traffic through the network, detection of network anomalies, and in same cases even automated responses to threats. At the same time, they support businesses in meeting regulatory requirements such as NIST, ISO 27001 or ISA/IEC 62443.
However, not every NIDS solution is suitable for every environment, especially in industrial and production contexts, where requirements can vary considerably from environment to environment. As such, we will have a look at and compare two market-leading NIDS solutions – Microsoft Defender for IoT and Nozomi Networks – based on technical documentation, field experience and realistic application scenarios:
Technical Features
NIDS Feature Comparison: Microsoft Defender for IoT vs. Nozomi Networks
| Feature |
Microsoft Defender for IoT |
Nozomi Networks |
| Asset Discovery |
Automatic, agentless, and deep protocol analysis based on common IT and OT protocols.
Limited transparency for field devices (e.g. BACnet, Profinet), if they do not communicate actively.
|
Deep packet inspection (DPI) with broad OT protocol support down to the field level.
Also reliably supports passive or older industrial environments.
|
| Threat Detection |
Behavior-based, signature-based, and anomaly detection using Microsoft Threat Intelligence.
OT-specific contexts or firmware bases are sometimes not recognized.
|
AI-powered threat detection, anomaly detection, and a correlation engine tuned for OT/IoT networks.
|
| Integration |
Deep native integration with Microsoft Azure services like Sentinel (SIEM), Purview (Governance), and Defender XDR.
Firewall automation only possible with additional effort.
|
Integrates well with major SIEMs, EDRs, or firewalls (Check Point, Palo Alto as per Nozomi Guide, Fortinet).
Pre-built playbooks available. Cisco firewalls are currently not supported for automated vulnerability rule setting.
|
| Vulnerability Management |
Based on fingerprinting. Built-in vulnerability assessments mapped against CVE databases,
industry-specific risks and recognized assets. May lead to misattributions or generic CVEs.
Manual validation required.
|
Strong vulnerability detection. Context-based CVE mapping with firmware awareness,
risk analysis based on risk scores and asset criticality evaluation.
|
| Cloud/On-Premises |
Hybrid model with cloud-first approach, edge sensors and cloud-native Azure management.
Of limited use in fully isolated environments.
|
Focus on on-premises operation, optionally with hybrid or full cloud management via the Nozomi Vantage platform.
Ideal for highly regulated or isolated OT networks.
|
| Firewall Integration |
Basic direct policy and rule integration possible with supported firewalls via Azure Sentinel.
No native playbooks for specific providers.
|
Advanced integration capabilities and detailed native playbooks for providers such as Palo Alto, Check Point, and Fortinet.
Automated firewall rule setting possible. Cisco firewall automation currently not available.
|
Technical Setup
NIDS Setup Comparison: Microsoft Defender for IoT vs. Nozomi Networks
| Setup Aspect |
Microsoft Defender for IoT |
Nozomi Networks |
| Deployment |
Lightweight, quick to deploy sensor approach with sensors deployed at key network points.
Fast implementation in Azure-centric environments. Additional infrastructure often required
for complete OT visibility (e.g., mirror ports).
|
Strategic sensor placement required, but complete visibility in return.
Supports physical and virtual appliances.
|
| Ease of Use |
Highly streamlined for Microsoft ecosystem customers.
Centralized control and operations via Azure dashboard.
Ideal for Microsoft-oriented IT/SOC teams.
|
Powerful but requires more manual fine-tuning and training,
particularly for highly customized networks. Designed specifically for OT teams.
Comprehensive customization of dashboards, alerts, and detection logic.
|
| Customization |
Medium. Preconfigured templates and customizable analytics within Azure.
Limited options for OT-specific requirements.
|
Highly customizable. Rules, playbooks, dashboards, and correlations
can be customized in detail. Strong in complex environments.
|
| Scalability |
Highly scalable via cloud-based Azure infrastructure.
Limitations within highly segmented or isolated networks.
|
Scalable across multiple locations, both on-premises and via Vantage SaaS.
Particularly suitable for distributed OT/IIoT networks.
May require multiple appliances for very large networks.
|
Cost Comparison
NIDS Cost Comparison: Microsoft Defender for IoT vs. Nozomi Networks
| Cost Aspect |
Microsoft Defender for IoT |
Nozomi Networks |
| Licensing Model |
Subscription per sensor, monitored asset, and cloud service usage.
Billing via Azure Marketplace.
|
Licensing per application or site/device monitored, plus software subscription.
|
| Initial Investment |
Low entry costs for cloud-first companies.
|
Higher, especially if many physical applications are required or on-premises operations.
|
| Operational Costs |
Pay-as-you-go billing. May increase with high data volumes.
|
Mostly predictable, fixed costs after hardware purchase.
Varies depending on support tiers and scope.
|
| Transparency |
Public prices available via Microsoft portals and Azure Marketplace.
|
Requires direct sales engagement. Less transparency in comparison.
|
After-Sales Support
NIDS Support Comparison: Microsoft Defender for IoT vs. Nozomi Networks
| Support Aspect |
Microsoft Defender for IoT |
Nozomi Networks |
| Support Channels |
Microsoft Premier Support, Unified Support, or Partner Support available.
24/7 hotline for critical incidents.
|
Global 24/7 support with direct engineering access for critical issues.
Dedicated technical account managers available.
|
| Community Resources |
Comprehensive public documentation, Microsoft Learn, GitHub resources,
and learning paths available.
|
Strong internal knowledge base, but fewer open community resources compared to Microsoft.
|
| Training |
Free and paid training available via Microsoft Learn.
Certifications available in Microsoft Security track.
|
Paid training and certification available for partners and customers.
|
| Updates and Patching |
Regular automatic updates via Azure, including threat feeds.
|
Regular automatic updates via Azure, including threat database.
Manual intervention sometimes required for on-premises operations.
|
Conclusion
Both options are top tier NIDS solutions. Businesses that require comprehensive integration with Microsoft Azure, rapid deployment, and cloud scalability, or that have already invested in Microsoft solutions should choose Microsoft Defender for IoT. Businesses that place particular value on highly customizable, granular monitoring of complex industrial environments in an on-premises model or have isolated networks should opt for Nozomi Networks. Ultimately, choosing the right solution depends on the business’s IT/OT stack, transparency requirements, response speed, and integration capabilities.
This is the third and final article in our NIDS series. Thank you for following along — and stay tuned for more insights on industrial cybersecurity.
