OT Asset Inventory: A Foundation for Securing Critical Infrastructure

On August 13, the Cybersecurity and Infrastructure Security Agency (CISA), the National Security Agency (NSA), and a coalition of global partners released Foundations for OT Cybersecurity: Asset Inventory Guidance for Owners and Operators. The guidance is clear: building and maintaining an authoritative OT asset inventory is foundational to defending critical infrastructure.

What the guidance says

The new report lays out a systematic approach for creating and sustaining OT asset inventories, including: 

• Defining scope and governance — establishing responsibility and authority for asset management.
• Identifying assets and attributes — cataloging not just devices but also key details like protocols, criticality, and vulnerabilities.
• Developing an OT taxonomy — classifying assets by function and criticality to support risk management, incident response, and resource prioritization.
• Managing data and lifecycle — centralizing asset information and ensuring inventories are updated as systems evolve.
• Post-inventory actions — using the inventory to drive vulnerability management, reliability planning, performance monitoring, and continuous improvement.

The document also provides sector-specific examples for energy, water/wastewater, and oil and gas, underscoring just how central asset inventory is across industries that depend on reliable OT systems.

The takeaway: without an up-to-date inventory, defenders can’t protect what they don’t know they have.

Why this matters now

Critical infrastructure—from manufacturing lines to utilities to LNG facilities—is a prime target for malicious actors. Passive scanning tools can provide partial visibility, but often capture only 50–60% of the environment. The rest of the assets—often the most critical—remain invisible without a proactive inventory approach.

This is why the guidance emphasizes taxonomy, governance, and lifecycle management. Asset inventory isn’t just about discovery—it’s about building a living system of record that supports security, reliability, and resilience.

NetBox is at the center of OT security architectures

Across industrial, energy, and utility sectors, organizations are increasingly turning to NetBox as their authoritative OT asset inventory.

• Full coverage: NetBox models every asset, including those that scanners can’t see.
• Digital twin for operations: Teams use NetBox to plan expansions, model changes, and ensure readiness before equipment is deployed.
• Integration hub: NetBox integrates with scanning, monitoring, and CMDB systems, becoming the connective tissue for OT security architectures and data.
• Trusted foundation: NetBox Labs works alongside the world’s largest and most experienced systems integrators to embed NetBox into our partners’ OT security reference architectures, helping manufacturing, industrial, and critical infrastructure operators deploy more complete OT defenses.

Even CISA’s own Malcolm project highlights NetBox as the inventory of choice for OT security in critical infrastructure environments.

A surging use case

The CISA/NSA guidance validates what our community is already experiencing: OT asset inventory is a surging use case for NetBox. From utilities to manufacturing to critical energy, teams are operationalizing NetBox to build defensible architectures, improve resilience, and protect the systems that matter most.Read the NSA announcement for more on this important guidance.